Check out this article:
http://www.atheists.org/christianity/didjesusexist.htmlIt really gets into the nitty gritty of it.
In the end, it's faith ... plain and simple.
The Romans persecuted the Jews, naturally the Jews used a different tool to overcome their persecutors. It was religion.
They didn't have weapons or power, but they had belief. A character that put the little man, the poor, up onto a pedistal. A man that said that a rich man can not get into Heaven.
Why question that logic huh?
I'm sure the Romans did, but the creation of the resurection and the son of God stuff ... well, that was and still is the exclamation point.
Without that the story would be as popular as Bram Stroker's "Dracula," and would be filed in the same category ... fiction.
Making it fact was the tool, the means to and end to overcome Roman rule and the Pegans. If Constantine didn't convert to Christianity, then I doubt it would have spread like it did. Eventually it would have died out and become excepted as myth.
Read the article in the link and see where you go from there.
If you want to believe in something believe in humankind and the ability to strive to make life better.
Like the words of Jesus? Cool ... I wish more people lived by the words attributed to Jesus. Doesn't really matter if they were made up or not, they are great words to live by.