Despite skeptical claims, it is entirely certain that Jesus existed, and that he had followers very soon after his death on the cross. Hence even non-Christians at the time conceded the fact of Jesus’ following. Jewish historian Josephus (AD 37-100) mentioned Jesus’ following in his history book, Antiquities of the Jews, written around 93-94 AD. He wrote this:

About this time there lived Jesus, a wise man, if indeed one ought to call him a man.  For he was one who performed surprising deeds and was a teacher of such people as accept the truth gladly. He won over many Jews and many of the Greeks. He was the Messiah. And when, upon the accusation of the principal men among us, Pilate had condemned him to a cross, those who had  first come to love him did not cease.  He appeared to them spending a third day restored to life, for the prophets of God had foretold these things and a thousand other marvels about him.  And the tribe of the Christians, so called after him, has still to this day not disappeared. Jewish Antiquities, 18.3.3 §63

There is credible evidence that this passage is not 100% accurate to the original text. This is because in this passage a Jew quotes Jesus as “the Messiah” and says Jesus was “restored to life.” While the passage is not 100% the same as the original writing, the main points of the passage are consistent with the original passage, according to a lot of historians.

This is great evidence that Christianity had gained a great following by the first century AD.

Jesus was not a dude that was made up by power-hungry leaders years after his death. Jesus was not a “good moral teacher” whose teachings have been interpreted differently since his death.

Jesus was a revolutionary, and he started a world-changing movement. His “Tribe of Christians” have changed World History.