Debating the existence of Jesus

[CleanShavenJesus]

I'm currently in a debate with a theist over whether or not Jesus existed.

Points he's made so far:
-Modern scholars agree Jesus existed, so he existed
-Tacticus and Josephus are reliable historians, so we should accept their accounts of Jesus.
-The writers of the Gospel died in very gruesome, martyr-like ways, so why would they die for something that wasn't even true?

Points I've made:
-Tacticus and Josephus were born AFTER the events of Jesus allegedly occurred, making their accounts as reliable as the Gospels (not very reliable)
-Josephus' account of Jesus was written after the first gospel was written.
-Josephus' "Testimonium Flavianum" was tampered with.
-Josephus' 'Jamesian Reference" refers to a different Jesus than Jesus Christ



So I've debunked his first two points (even though he won't acknowledge I have), but he keeps flaunting that third point of his. Any recommendations on how to end this debate in my favor, whether it be debunking the third point or addressing a new point?