Quote: How could "Jesus" be a historical figure when the name didn't exist until the 16th or 17th Century?
"J" as a separate English letter did not exist. The muslims still call the fucker Issa. The Greeks called him Iesou.
Gaius Julius Caesar was known as Iulius Caesar and Brutus was Marcus Iunius Brutus.
For that matter, "W" did not exist until the Middle Ages, either. But they got as close as they could on the sounds.