Did Jesus of Nazareth exist? It is quite possible. Did he intend to start a religion called Christianity? No, very unlikely.
I always like to emphasize the point with any Christian I'm having a religious discussion with that their 'god' was actually Jewish. He was an apocalyptic rabbi who thought his Heavenly Father was going to fix all the world's problems in his life time. He wrote nothing down. There is no evidence in the archeological record that speaks about him. They have yet to find pottery, stone or clay shard, or papyrus that is authentic that mentions him. So this all important, Son of God, the supposedly most important human being of all time, was not written about until after he died? It seems odd to me that if his intention was to start a new religion, that if he was this ultimate, uber important, 'perfect' man, that he would have penned, er, I mean, chiselled or quilled, something or there would have been a lot more written about him than what exists today.
Christianity was invented after Jesus died. The ancient religionists borrowed a lot from previous belief systems, they separated evil from God by creating Satan and original sin, which led to the need for a saviour and the church. Why is this? Seems to me it's about power and controlling the masses. Follow the money. It's also about arrogance... most religion seems to have this ideal that 'my god is better than your god'. In ancient times, I think it was about these things but also an attempt at bringing some sort of standardization and stability to the warring tribes of the Middle East. Seems we're still waiting for that to occur, just like Christians are still waiting for Jesus to return.
When I listen to Christian sermons, I wait for it... you know, that moment in the talk where they lay all the blame and guilt on your shoulders and tell you it's all your fault, you're a sinner, you aren't good enough so you need to pray more, confess more, work more as Christ's disciple, and definitely, donate more. It's an interesting exercise... I've yet to see it fail. It happens anywhere from about 1/3 to 1/2 way through the sermon. Check it out next time you listen to something like this... if you can stomach it that is.