We have some really weak records that some dude existed.
That doesn't mean anything about why your mythology is true. We also have records of lots of people who millions believed were divine.
But heres another thing: You are not a Christian because it's Truth.
You're a Christian because your parents were. That's it. That's the main reason you believe what you do and swear it is real. You happened to be born into it.
Same as how 99.9999% of Hindus are only Hindu because their parents were, or Muslims, or etc. They also believe what they do not because it's the Real Truth. But because of where they were born. Which is a really, really weak reason.
...And anyway - there's a whole lot more people alive today who believe in other religions; why should I believe yours over theirs?