The belief that Christianity came to Rome only through the lowest social classes, not working its way up until the time of Constantine, has been responsible for overlooking one of the most vital historical documents of all. The correspondence between Paul and the famous Stoic philosopher Seneca was preserved in the early church, accepted as genuine by the scholarly church fathers Jerome and Augustine, but categorically rejected as spurious by modern critics. Ernst Bickel believed that it originated in the 3rd century. "This correspondence presents a mythical expression of the historical process of fusion which came about in Italy...of Christianity on the one hand and, on the other, the ancient culture of the rhetoricians."

Seneca, in Jerome's words, was "the teacher of Nero and the most influential man of that time." The letters, some of them with exact dates expressed in terms of the consuls actually in office, sound natural, without any defensiveness such as would be expected if they were forgeries. They are written in just the way an open-minded intellectual of the period would write if he had taken an interest in a new religion from a foreign source being presented as another philosophy. If, as the pesher of Acts indicates, Paul was a member of the court of Agrippa II , then he was of sufficient social standing to meet and converse with the eminent philosopher. The later letters show that Seneca was protecting Paul and the Christians from the venom of Nero in the period leading up to the great fire of 64 AD. This accords with the fact that Seneca, who had been tutor of the young Nero, had lost the favour of the capricious emperor, who ordered him to commit suicide, an order he had to obey with the courage of a Stoic in 65 AD.

The letters begin at the outset of Nero's reign at the end of 54 AD. In the first, Seneca from Rome writes to Paul, who at the end of that year was in Ephesus. The two had previously met, possibly in Athens in 51 AD, where Paul had debated with Stoic and Epicurean philosophers (Acts 17:18):

"Paul, you have been told, I believe, that yesterday we had a conversation with our Lucilius about the Apocrypha and other things. There were with me some members of your school. For we had retreated into Sallust's garden, where, by a happy chance for us, the people I have just mentioned, although they meant to go elsewhere, caught sight of us and joined us. We certainly longed for your presence, and I would like you to know that after the reading of your booklet, that is of a number of letters which you have addressed to city churches or to the chief cities of provinces and which contain wonderful exhortations for the moral life, we are thoroughly refreshed.."

Paul replies that he has received Seneca's letter with joy, saying that he considered himself honoured by "this judgment of a sincere man", one who was "the censor, philosopher and teacher of so distinguished a prince".

Seneca saw this as a hint to bring Paul to the attention of the emperor. He writes: " I have arranged some scrolls and have brought them into a definite order corresponding to their several divisions. Also I have decided to read them to the emperor. If only fate ordains it favourably that he shows new interest, then perhaps you too will be present; otherwise I shall fix a day for you at another time when together we may examine this work. And if only it could be done safely, I would not read this writing to him before meeting you. You may then be certain that you are not being overlooked. Farewell, most beloved Paul."

Paul's reply speaks of his desire for being with Seneca, indicating politely that Seneca should come to see him. At this time, in the years AD 55-57, Paul was still in Ephesus. He writes "As soon then as you set about coming, we shall see one another and do so at close quarters." But apparently Seneca thought that Paul should come to see him in Rome, writing:

"Your staying away, being all too long, distresses us. What then is wrong? what keeps you away? If it is the empress's (Poppaea Sabina's ) displeasure because you have wandered away from the ancient rites and beliefs (of Judaism) and become a convert elsewhere, then you may find opportunity to convince her that this has resulted from deliberation and not from levity."

Poppaea was currently the mistress of Nero. She subsequently became his second wife, and as empress exercised strong influence on Jewish affairs, showing partiality to orthodox Pharisaism. Josephus, whom she helped in a dispute brought to Rome, describes her as a "worshipper of God" (Ant. 20, 195). From her perspective and that of orthodox Judaism, Christians had "wandered away" from Judaism.

Awareness of Poppaea's influence accounts for the guarded tone of Paul's next letter:

"I may not express myself with pen and ink regarding the matters about which you have written to me, of which the first indicates something distinctly whilst the last shows it too apparently, especially as I know that under you, that is among you and in your midst, there are people who understand me. We must treat all with respect, particularly when they strain after an opportunity to express their displeasure. If we have patience with them, we shall overcome them in every way and in every respect, provided only they are men who can show that they regret what they have done. Farewell."

In the seventh letter, Seneca speaks favourably of Paul's epistles "to the Galatians, to the Corinthians and to the Achaians". "And that nothing may be concealed from you, beloved brother, or burden my conscience, I confess that your thoughts have made an impression on Augustus (Nero)." Nero had expressed wonder that a man "who had not had the usual education was capable of such thoughts".

Paul's reply shows that he no longer trusted Nero. "Your design to bring to his notice what contradicts his beliefs and tenets was misplaced......You do it all out of a love of me that is much too great. I beg you for the future not to do any such thing again. For you must be wary lest in loving me you offend his mistress (Poppaea); her disfavour will indeed do no harm if she continues in it, nor will it avail anything if that does not happen; as queen she will not feel displeasure, but as a woman she will take offence".

Seneca then offers an apology: "If in the past a mistake has been made, you will grant me forgiveness".

The next few letters have exact dates, the first, from Paul, written June 27, AD 58 , implying that he is too lowly a person to have his name associated with Seneca's, and calling him "my highly revered teacher". The chronology of Acts shows that Paul was in Jerusalem at that time. Seneca in Rome would not have received Paul's letter when he wrote on July 6, AD 58 (letter 13, misplaced in the collection), saying nothing about the court but advising Paul to improve his literary style. "Have regard to the Latinity and make use of outward form for beautiful words".

Paul writes again on August 1, AD 58, now giving Seneca pastoral advice: "Make yourself a new herald of Jesus Christ". This would procure an access for the teaching to "the temporal king (Nero) and his servants and true friends, although what you are persuaded of will be to them hard and incomprehensible".

On March 23, AD 59, Seneca reassures Paul about his worthiness to use Seneca's name, calling himself "your Seneca". "I am so very near to you that I count as your second self...you are not unworthy to be named first in the letters...all the more since you are a Roman citizen".

There is then a gap until a letter dated March 28, AD 64, in which Seneca begins: "Can you possibly think that I am not distressed and grieved that capital punishment is still visited upon you innocent persons? As also that all the people are convinced of your cruelty and criminal malignity, believing that all evil in the city is owing to you".

The fire for which Nero blamed Christians would take place July 19 of that year. It is possible that Seneca began the letter in March and did not correct the date when he finished it after the fire, writing:

"As regards fire, it is clear as the day at whose hands the Roman capital has to suffer it so often... Christians and Jews are executed as fire-raisers, as commonly happens. This rowdy, whoever he is that finds pleasure in murder and uses lies as a disguise, is destined for his own time; and as the best is sometimes sacrificed as one life for many, so also will this accursed one be burned in the fire for all. 132 palaces, 4000 apartment houses were burned down in six days; the seventh day brought a pause."

Despite the continuing resistance of modern critics to the idea that Christianity came from the outset to the highest Roman social circles, these letters are further proof of what is given by the pesher, that it was in the court of Agrippa II that Peter and Paul succeeded in establishing Christian practice, and from that court it came directly to the Roman imperial court.