On the Jesus myth theory...

I've been apt to view Jesus as little more than a folk tale, as I was raised by atheists and never had a reason to treat the bible as more than literature. My view is based on having never seen much about him outside of the Bible other than Jocephus' writings after Jesus' alleged death. An outside account from the same era as the post-mortem folk tales of a character hardly seems sufficient as evidence. Add to this the lack of contemporary accounts, and it's hard for me to say I really have any reason to think the guy was more than a legend.

Now, I try my best to be a good skeptic and a critical thinker, but I've been having a difficult time figuring out why biblical scholars are fairly certain of Jesus' existence. Am I missing some evidence? I say this sincerely, this isn't an attempt to troll anyone into an argument. I'd really like to hear more detailed evidence as to why it's generally accepted that he existed as a living, breathing human being.

Thanks r/atheism!

Edit: Forgot to mention that the Osiris-Dionysus argument is also a pretty compelling argument about the mythological aspects of Jesus.