I am sure god doesn't exist, I am as sure it does not exist as you are that it does, unless of course you admit that you believe there is a chance that god is not real...
Jesus lived 2000 yrs ago, in a time where there was no reliable way to document anything, his life is told in books written decades and centuries after his death.....there is little to no actual evidence of Jesus outside of the bible.....he may not even have been a real person. Though I do think someone similar to a " Jesus" did actually live though obviously he was not the son of god etc....still the point is these stories and the religion that grew around them are in no way proof there is a god and certainly do not provide any real evidence of any sort that there is a god.
There were hundreds if not thousands of religions that existed before Christianity and frankly Christianity borrows from many of them.....
Thankfully you continue to be drawn to debate something you are for sure does not exist. That means there is hope.