The abundance of evidence show that NT Jesus was made up- a non-historical character- fabricated with fiction, implausibilities and mythology found in Jewish, Greek and Roman religious writings.
The next and extremely important question is when was NT Jesus fabricated??
Answering that question using the available evidence will make us understand when the Jesus cult likely started.
NT authors and apologetic sources place their made up character called Jesus in the time of Pilate who was a Roman Governor c 26-36 CE.
A significant clue to determine when the NT Jesus was made up is found in the Gospels.
Examine gMark 13
gMark
13. 1 As he was going out of the temple, one of his disciples said to him, “Teacher, look! What massive stones! What impressive buildings!”
2 Jesus said to him, “Do you see these great buildings? Not one stone will be left upon another—all will be thrown down.”
So it would appear that the fabricated NT Jesus correctly predicted the Fall of the Jewish Temple about 35 years before it happened.
It was not really a prediction.
The anonymous authors of the Jesus stories were writing their fiction after c 70 CE or after the Fall of the Jewish Temple.
The Jesus cult, believers in the Jesus stories, could not have been before c 70 CE or before the Fall of the Temple.
Apologetic writers of antiquity claimed it was prophesied in Hebrew Scripture that the Fall of the Temple c 70 CE was the sign that their invented Jewish Messiah had already come.
Tertullian's Answer to the Jews 8
Accordingly the times must be inquired into of the predicted and future nativity of the Christ, and of His passion, and of the extermination of the city of Jerusalem, that is, its devastation. For Daniel says, that both the holy city and the holy place are exterminated together with the coming Leader, and that the pinnacle is destroyed unto ruin...
Justin's Dialogue with Trypho
Accordingly, these things have happened to you in fairness and justice, for you have slain the Just One, and His prophets before Him; and now you reject those who hope in Him, and in Him who sent Him--God the Almighty and Maker of all things...
Celsus' Against Celsus
Now this writer, although not believing in Jesus as the Christ, in seeking after the cause of the fall of Jerusalem and the destruction of the temple, whereas he ought to have said that the conspiracy against Jesus was the cause of these calamities befalling the people, since they put to death Christ...
Their fiction character called Jesus could not have been killed by the Jews.
Their invented Jesus is not found anywhere in Hebrew Scripture.
Their invented Jesus is not found in any non-apologetic writings by supposed contemporaries.
It was the Fall of the Temple c 70 CE that caused anonymous authors to invent propaganda and conspiracy theories to blame the Jews.
Some of the people who believed those fiction stories of the fabricated character are those who started the Jesus cult.
The Jesus story and cult must have started after the c 70 CE, after the Fall of the Jewish.
All Epistles by anyone [Paul or not] to Jesus cults must have been after the cult was already started.
In other words, every NT writing must have been composed after c 70CE or after the Fall of the Jewish Temple.