There are two big problems with atheism:
One, it almost has to go hand in hand with believing in evolution, and evolution has been overwhelmingly disproven.
And two, there is an irrefutable historical case to be made that Jesus was seen by large numbers of people over a period of 40 days or thereabouts beginning three days after he had been crucified.
The stories about walking on water or changing water to wine you can take or leave but the story about the resurrection cannot be pooh-poohed. At the time when Jesus lived, several centuries had passed since the old religious practices intended to communicate with the spirit world directly had ceased to work, and by that I mean prophets, the Greek oracles, "familiar spirits" such as the familiar ghost story in the OT involving King Saul, the prophet Samuel, and the "witch" of Endor, electrostatic devices like the pyramids or the "ark", and a number of other things. Zechariah even went so far as to admonish parents to simply kill children who went on trying to do prophecy kinds of things, because the information which the practice had produced in past ages had turned into mush.
People were starting to become atheists and evolutionites even as they are now. Jesus basically said something like "Hey, I'm going to DEMONSTRATE the basic problem with these ideas in such a way as to leave no doubt in anybody's mind, I'm going to simply hand myself over the the pharisees and Romans and let them kill me in their usual gruesome fashion, and then in three days I'm going to come BACK, and then proceeded to do just that so that NOBODY needs to be an atheist.