Let’s be generous. Let’s assume that every single one of the gospels and every single New Testament Book and Letter is a different, independent source. (This is being way generous, since lots of the letters are known to be by the same person; and since the first three gospels are almost certainly taken from the same source material, not eye-witness accounts; However, let’s not quibble.)
So we have, what, fewer that forty texts that mention Jesus. These are all texts written by people who believed Jesus was divine, and written by people who were trying to start a new religion and convert followers. You can’t exactly call them unbiased.
The only outside historian to mention Jesus is Josephus, and that reference is almost certainly a later addition. (Josephus was a brown-noser, who wrote whatever his patron wanted to hear; his patron would have been very anti-Christian, so it is highly unlikely that Josephus would have written glowing words about Jesus. And, IIRC, a copy of Josephus exists that does NOT have the added phrases about how brilliant and popular Jesus was.)
Someone mentioned the Koran, but that’s 600 years later. By that time, Christianity was a major religion.
There is no record of Jesus on the tax rolls. There is no letter from Pontius Pilate to Caesar saying, “Wow, this Jesus guy is a pain in the butt, how about I bump him off.” There is no letter from Mary to her cousin in Rome about how her son doesn’t want to be a carpenter, he wants to go to Gallilee and start a religion. There is no outside, independent evidence.
OK, now, let’s look at Caesar or George Washington or…
First off, we have texts written by Caesar. We have tons of legal documents, tax rolls, recordings of speeches in the Senate, lists of property owned and taxes paid, documents issued in Caesar’s name, dedications on buildings, – the list is endless. And, more to the point, these are INDEPENDENT writings. Their purpose was not to convert folks to a new religion and they had no ulterior motive in mentioning him.