The first century a.D. evangelist Paul of Tarsus was one of the earliest and most important Christian teachers.  As a "hellenized" Jewish citizen of Rome, Paul had a background in both the Jewish teachings of the Torah and the Greek-language philosophy and culture which predominated in the wider Roman empire. Moreover, Paul was able to travel freely throughout that empire at a time when not all Jews, many of whom lacked official Roman citizenship, could. Paul styled himself the "apostle to the Gentiles (non-Jews)," and sought to spread his interpretation of the Christian faith beyond the comparatively narrow confines of the Jewish community of Palestine. In doing so, he helped begin the transformation of Christianity from a solely Jewish religious movement into a creed which was predominantly non-Jewish (and indeed, after several centuries, even anti-Jewish). At least seven letters by Paul to various early Christian communities eventually became part of the New Testament canon (there are five more attributed to him in the canon, but  many scholars suspect they are pseudepigraphic). Excerpted below are his letters to congregations in Roman and Ephesus, which present a view of what some of the earliest Christians believed.

Excerpts from the Letters of Paul
(Open English Bible, OEB)

Excerpts from Paul's Letter to the Romans

Chapter 1

From Paul, a servant of Jesus Christ, who has been called to become an apostle, and has been set apart to tell God's good news. 2 This good news God promised long ago through his prophets in the sacred scriptures, 3 concerning his Son, Jesus Christ, our Lord; who, as to his human nature, was descended from David, 4 but, as to the spirit of holiness within him, was miraculously designated Son of God by his resurrection from the dead. 5 Through him we received the gift of the apostolic office, to win submission to the faith among all nations for the glory of his name. 6 And among these nations are you — you who have been called to belong to Jesus Christ.

7 To all in Rome who are dear to God and have been called to become Christ's people, may God, our Father, and the Lord Jesus Christ bless you and give you peace.

8 First, I thank my God through Jesus Christ for you all, because the report of your faith is spreading throughout the world. 9 God, to whom I offer the worship of my soul as I tell the goodness of his Son, is my witness how constantly I mention you when I pray, 10 asking that, if he be willing, I may some day at last find the way open to visit you. 11 For I long to see you, in order to impart to you some spiritual gift and so give you fresh strength — 12 or rather that both you and I may find encouragement in each other's faith. 13 I want you to know, my friends, that I have many times intended coming to see you — but until now I have been prevented — that I might find among you some fruit of my labors, as I have already among the other nations.
Faith the Ground of Acceptance

14 I have a duty to both the Greek and the barbarian, to both the cultured and the ignorant. 15 And so, for my part, I am ready to tell the good news to you also who are in Rome.

16 For I am not ashamed of the good news; it is the power of God which brings salvation to everyone who believes, to the Jew first, but also to the Greek. 17 For in it there is a revelation of the divine righteousness resulting from faith and leading on to faith; as scripture says — ‘Through faith the righteous will find life.’

18 So, too, there is a revelation from heaven of the divine wrath against every form of ungodliness and wickedness on the part of those people who, by their wicked lives, are stifling the truth. 19 This is so, because what can be known about God is plain to them; for God himself has made it plain. 20 For ever since the creation of the universe God's invisible attributes — his everlasting power and divinity — are to be seen and studied in his works, so that people have no excuse; 21 because, although they learned to know God, yet they did not offer him as God either praise or thanksgiving. Their speculations about him proved futile, and their undiscerning minds were darkened. 22 Professing to be wise, they showed themselves fools; 23 and they transformed the glory of the immortal God into the likeness of mortal humans, and of birds, and beasts, and reptiles.

24 Therefore God abandoned them to impurity, letting them follow the cravings of their hearts, until they dishonored their own bodies; 25 for they had substituted a lie for the truth about God, and had reverenced and worshiped created things more than the Creator, who is to be praised for ever. Amen. 26 That, I say, is why God abandoned them to degrading passions. Even the women among them perverted the natural use of their bodies to the unnatural; 27 while the men, disregarding that for which women were intended by nature, were consumed with passion for one another. Men indulged in vile practices with men, and incurred in their own persons the inevitable penalty for their perverseness.

28 Then, as they would not keep God before their minds, God abandoned them to depraved thoughts, so that they did all kinds of shameful things. 29 They reveled in every form of wickedness, evil, greed, vice. Their lives were full of envy, murder, quarreling, treachery, malice. 30 They became back-biters, slanderers, impious, insolent, boastful. They devised new sins. They disobeyed their parents. 31 They were undiscerning, untrustworthy, without natural affection or pity. 32 Well aware of God's decree, that those who do such things deserve to die, not only are they guilty of them themselves, but they even applaud those who do them.

Chapter 2

1 Therefore you have nothing to say in your own defense, whoever you are who set yourself up as a judge. In judging others you condemn yourself, for you who set yourself up as a judge do the very same things. 2 And we know that God's judgment falls unerringly on those who do them. 3 You who judge those that do such things and yet are yourself guilty of them — do you suppose that you of all people will escape God's judgment? 4 Or do you think lightly of his abundant kindness, patience, and forbearance, not realizing that his kindness is meant to lead you to repentance? 5 Hard-hearted and impenitent as you are, you are storing up for yourself wrath on the ‘day of wrath,’ when God's justice as a judge will be revealed; 6 for ‘he will give to everyone what their actions deserve.’ 7 To those who, by perseverance in doing good, aim at glory, honor, and all that is imperishable, he will give immortal life; 8 while as to those who are factious, and disobedient to truth but obedient to evil, wrath and anger, distress and despair, 9 will fall on every human being who persists in wrong-doing — on the Jew first, but also on the Greek. 10 But there will be glory, honor, and peace for everyone who does right — for the Jew first, but also for the Greek, 11 since God shows no partiality. 12 All who, when they sin, are without Law will also perish without Law; while all who, when they sin, are under Law, will be judged as being under Law. 13 It is not those who hear the words of a Law that are righteous before God, but it is those who obey it that will be pronounced righteous. 14 When Gentiles, who have no Law, do instinctively what the Law requires, they, though they have no Law, are a Law to themselves; 15 for they show the demands of the Law written on their hearts; their consciences corroborating it, while in their thoughts they argue either in self-accusation or, it may be, in self-defense — 16 on the day when God passes judgment on people's inmost lives, as the good news that I tell declares that he will do through Christ Jesus.

17 But, perhaps, you bear the name of ‘Jew,’ and are relying on Law, and boast of belonging to God, and understand his will, 18 and, having been carefully instructed from the Law, have learned to appreciate the finer moral distinctions. 19 Perhaps you are confident that you are a guide to the blind, a light to those who are in the dark, an instructor of the unintelligent, 20 and a teacher of the childish, because in the Law you possess the outline of all knowledge and truth. 21 Why, then, you teacher of others, don't you teach yourself? Do you preach against stealing, and yet steal? 22 Do you forbid adultery, and yet commit adultery? Do you loathe idols, and yet plunder temples? 23 Boasting, as you do, of your Law, do you dishonor God by breaking the Law? 24 For, as scripture says — ‘The Gentiles insult God's name because of you’! 25 Circumcision has its value, if you are obeying the Law. But, if you are a breaker of the Law, your circumcision is no better than uncircumcision. 26 If, then, an uncircumcised man pays regard to the requirements of the Law, won't he, although not circumcised, be regarded by God as if he were? 27 Indeed, the person who, owing to his birth, remains uncircumcised, and yet scrupulously obeys the Law, will condemn you, who, for all your written Law and your circumcision, are yet a breaker of the Law. 28 For a man who is only a Jew outwardly is not a real Jew; nor is outward bodily circumcision real circumcision. The real Jew is the person who is a Jew in soul; 29 and the real circumcision is the circumcision of the heart, a spiritual and not a literal thing. Such a person wins praise from God, though not from people.

Chapter 3

1 What is the advantage, then, of being a Jew? Or what is the good of circumcision? 2 Great in every way. First of all, because the Jews were entrusted with God's utterances. 3 What follows then? Some, no doubt, showed a want of faith; but will their want of faith make God break faith? Heaven forbid! 4 God must prove true, though everyone prove a liar! As scripture says of God — ‘That you may be pronounced righteous in what you say, and gain your cause when people would judge you.’

5 But what if our wrong-doing makes God's righteousness all the clearer? Will God be wrong in inflicting punishment? (I can but speak as a person.) Heaven forbid! 6 Otherwise how can God judge the world?

7 But, if my falsehood redounds to the glory of God, by making his truthfulness more apparent, why am I like others, still condemned as a sinner? 8 Why should we not say — as some people slanderously assert that we do say — ‘Let us do evil that good may come’? The condemnation of such people is indeed just!

9 What follows, then? Are we Jews in any way superior to others? Not at all. Our indictment against both Jews and Greeks was that all alike were in subjection to sin. 10 As scripture says —

   ‘There is not even one who is righteous,
     11 not one who understands,
     not one who is searching for God!
   12 They have all gone astray;
     they have one and all become depraved;
       there is no one who is doing good — no, not one!’
   13 ‘Their throats are like opened graves;
     they deceive with their tongues.’
   ‘The venom of snakes lies behind their lips,’
     14 ‘And their mouths are full of bitter curses.’
   15 ‘Swift are their feet to shed blood.
   16 Distress and trouble dog their steps,
     17 and the path of peace they do not know.’
       18 ‘The fear of God is not before their eyes.’

19 Now we know that everything said in the Law is addressed to those who are under its authority, in order that every mouth may be closed, and to bring the whole world under God's judgment. 20 For ‘no human being will be pronounced righteous before God’ as the result of obedience to Law; for it is Law that shows what sin is.

21 But now, quite apart from Law, the divine righteousness stands revealed, and to it the Law and the prophets bear witness — 22 the divine righteousness which is bestowed, through faith in Jesus Christ, on all, without distinction, who believe in him. 23 For all have sinned, and all fall short of God's glorious ideal, 24 but, in his loving kindness, are being freely pronounced righteous through the deliverance found in Christ Jesus. 25 For God set him before the world, to be, by the shedding of his blood, a means of reconciliation through faith. And this God did to prove his righteousness, and because, in his forbearance, he had passed over the sins that people had previously committed; 26 as a proof, I repeat, at the present time, of his own righteousness, that he might be righteous in our eyes, and might pronounce righteous the person who takes their stand on faith in Jesus.

27 What, then, becomes of our boasting? It is excluded. By what sort of Law? A Law requiring obedience? No, a Law requiring faith.

28 For we conclude that a person is pronounced righteous on the ground of faith, quite apart from obedience to Law. 29 Or can it be that God is the God only of the Jews? Isn't he also the God of the Gentiles? 30 Yes, of the Gentiles also, since there is only one God, and he will pronounce those who are circumcised righteous as the result of faith, and also those who are uncircumcised on their showing the same faith.

31 Do we, then, use this faith to abolish Law? Heaven forbid! No, we establish Law.

Chapter 4

1 What then, it may be asked, are we to say about Abraham, the ancestor of our nation? 2 If he was pronounced righteous as the result of obedience, then he has something to boast of. Yes, but not before God. 3 For what are the words of scripture? ‘Abraham had faith in God, and his faith was regarded by God as righteousness.’ 4 Now wages are regarded as due to the person who works, not as a favor, but as a debt; 5 while, as for the person who does not rely on their obedience, but has faith in him who can pronounce the godless righteous, their faith is regarded by God as righteousness.

6 In precisely the same way David speaks of the blessing pronounced on the person who is regarded by God as righteous apart from actions — 7 ‘Blessed are those whose wrong-doings have been forgiven and over whose sins a veil has been drawn! 8 Blessed the man whom the Lord will never regard as sinful!’ 9 Is this blessing, then, pronounced on the circumcised only or on the uncircumcised as well? We say that — ‘Abraham's faith was regarded by God as righteousness.’ 10 Under what circumstances, then, did this take place? After his circumcision or before it? 11 Not after, but before. And it was as a sign of this that he received the rite of circumcision — to show the righteousness due to the faith of an uncircumcised man — in order that he might be the father of all who have faith in God even when uncircumcised, so that they also may be regarded by God as righteous; 12 as well as father of the circumcised — to those who are not only circumcised, but who also follow our father Abraham in that faith which he had while still uncircumcised. 13 For the promise that he should inherit the world did not come to Abraham or his descendants through Law, but through the righteousness due to faith. 14 If those who take their stand on Law are to inherit the world, then faith is robbed of its meaning and the promise comes to nothing! 15 Law entails punishment; but, where no Law exists, no breach of it is possible. 16 That is why everything is made to depend on faith: so that everything may be God's gift, and in order that the fulfillment of the promise may be made certain for all Abraham's descendants — not only for those who take their stand on the Law, but also for those who take their stand on the faith of Abraham. (He is the Father of us all; 17 as scripture says — ‘I have made you the Father of many nations.’) And this they do in the sight of that God in whom Abraham had faith, and who gives life to the dead, and speaks of what does not yet exist as if it did. 18 With no ground for hope, Abraham, sustained by hope, put faith in God; in order that, in fulfillment of the words — ‘So many will your descendants be,’ he might become ‘the Father of many nations.’ 19 Though he was nearly a hundred years old, yet his faith did not fail him, even when he thought of his own body, then utterly worn out, and remembered that Sarah was past bearing children. 20 He was not led by want of faith to doubt God's promise. 21 On the contrary, his faith gave him strength; and he praised God, in the firm conviction that what God has promised he is also able to carry out. 22 And therefore his faith ‘was regarded as righteousness.’ 23 Now these words — ‘it was regarded as righteousness’ — were not written with reference to Abraham only; 24 but also with reference to us. Our faith, too, will be regarded by God in the same light, if we have faith in him who raised Jesus, our Lord, from the dead; 25 for Jesus ‘was given up to death to atone for our offenses,’ and was raised to life that we might be pronounced righteous.

Chapter 13

13 Let everyone obey the supreme Authorities. For no Authority exists except by the will of God, and the existing Authorities have been appointed by God. 2 Therefore he who sets himself against the authorities is resisting God's appointment, and those who resist will bring a judgment on themselves. 3 A good action has nothing to fear from Rulers; a bad action has. Do you want to have no reason to fear the Authorities? Then do what is good, and you will win their praise. 4 For they are God's servants appointed for your good. But, if you do what is wrong, you may well be afraid; for the sword they carry is not without meaning! They are God's servants to inflict his punishments on those who do wrong. 5 You are bound, therefore, to obey, not only through fear of God's punishments, but also as a matter of conscience. 6 This, too, is the reason for your paying taxes; for the officials are God's officers, devoting themselves to this special work. 7 In all cases pay what is due from you — tribute where tribute is due, taxes where taxes are due, respect where respect is due, and honor where honor is due.
Excerpts from Paul's Letter to the Ephesians
Chapter 5

1 Be kind to one another, tenderhearted, ready to forgive one another, just as God, in Christ, forgave you. 5 Therefore imitate God, as his dear children, 2 and live a life of love, following the example of the Christ, who loved you and gave himself for you as ‘an offering and a sacrifice to God, that should be fragrant and acceptable.’

3 As for sexual immorality and every kind of impurity, or greed, do not let them even be mentioned among you, as befits Christ's people, 4 nor shameful conduct, nor foolish talk or jesting, for they are wholly out of place among you; but rather thanksgiving. 5 For of this you may be sure — that no one who is unchaste or impure or greedy of gain (for to be greedy of gain is idolatry) has any place awaiting him in the kingdom of the Christ and God.

6 Do not let anyone deceive you with specious arguments. Those are the sins that bring down the wrath of God on the disobedient. 7 Therefore have nothing to do with such people. 8 For, although you were once in darkness, now, by your union with the Lord, you are in the light. Live as ‘children of light’ — 9 For the outcome of life in the light may be seen in every form of goodness, righteousness, and sincerity — 10 Always trying to find out what is pleasing to the Lord. 11 Take no part in deeds of darkness, from which no good can come; on the contrary, expose them. 12 It is degrading even to speak of the things continually done by them in secret. 13 All such actions, when exposed, have their true character made manifest by the light. 14 For everything that has its true character made manifest is clear as light. And that is why it is said —

   ‘Sleeper, awake!
   Arise from the dead,
     And the Christ will give you light!’

15 Take great care, then, how you live — not unwisely but wisely, 16 making the most of every opportunity; for these are evil days. 17 Therefore do not grow thoughtless, but try to understand what the Lord's will is. 18 Do not drink wine to excess, for that leads to profligacy; but seek to be filled with the Spirit of God, and speak to one another in psalms and hymns and sacred songs. 19 Sing and make music in your hearts to the Lord. 20 Always give thanks for everything to our God and Father, in the name of our Lord Jesus Christ.

21 Submit to one another because you honor and respect Christ.

22 Wives should submit to their husbands as submitting to the Lord. 23 For a man is the head of his wife, as the Christ is the head of the church — being indeed himself the Savior of his body. 24 But as the church submits to the Christ, so also should wives submit to their husbands in everything. 25 Husbands, love your wives, just as the Christ loved the church, and gave himself for her, 26 to make her holy, after purifying her by the washing with the water, according to his promise; 27 so that he might himself bring the church, in all her beauty, into his own presence, with no spot or wrinkle or blemish of any kind, but that she might be holy and faultless. 28 That is how husbands ought to love their wives — as if they were their own bodies. A man who loves his wife is really loving himself; 29 for no one ever yet hated his own body. But everyone feeds his body and cares for it, just as the Christ for the church; 30 for we are members of his body.

   31 ‘For this cause a man will leave his father and mother, and be united to his wife; and the man and his wife will become one.’

32 In this there is a profound truth — I am speaking of Christ and his church. 33 However, for you individually, let each love his wife as if she were himself; and the wife be careful to respect her husband.

Chaper 6

Children, obey your parents, as children of the Lord; for that is but right. 2 ‘Honor your father and mother’ — this is the first Commandment with a promise — 3 ‘So that you may prosper and have a long life on earth.’ 4 And fathers, do not irritate your children, but bring them up with Christian discipline and instruction.

5 Slaves, obey your earthly masters, with anxious care, giving them ungrudging service, as if obeying the Christ; 6 not only when their eyes are on you, as if you had merely to please people, but as slaves of Christ, who are trying to carry out the will of God. 7 Give your service heartily and cheerfully, as working for the Master and not for people; 8 for you know that everyone will be rewarded by the Master for any honest work that he has done, whether he is a slave or free. 9 And masters, treat your slaves in the same spirit. Give up threatening them; for you know that he who is both their Master and yours is in heaven, and that before him there is no distinction of rank.