Josephus
The Babylonian Talmud
Pliny the Younger
Mara bar-Serapion
Tacitus
The existence of JC is the mainstream position, but there is also number of scholars with serious doubts about it. We cannot know for sure because we cannot travel to the past. I think JC is a myth, that's just my personal opinion.
We are in a forum where photos and videos are not valid evidence because they can be manipulated. The shape of the earth is questioned and gravity is denied. In the context of this forum I would expect to treat evidence of the life of JC with the same level of skepticism.
If photos from space are not valid evidence of the shape of the earth, then we can hardly accept manuscripts dated centuries after the alleged dead of JC, with few exceptions written after the 2nd century AC or later or manuscripts with clear manipulations.
Stash already did Mara bar-Serapion and Pliny the younger.
Isn't the Talmud part of the bible? you are using the bible as evidence of the bible. All Jesus citations in the Talmud can be disputed as well. In many of them it's not even clear if they are really referring to Jesus. Besides that the Babylonian Talmud was completed around 500 AC and edited for another two centuries. If you show me a manuscript contemporary to JC that mentions him then it will be a good evidence, but something written hundreds of years later is just too much. It's only people writing about things that happened centuries ago.
Tacitus was born in 56 ac, too late to witness anything, that's why it's also questioned by some scholars. He was just told something and he wrote it. Why should I believe that? The copy I have found is from the 11th century, but maybe you know of an earlier one?
I'm sure you can provide more sources, but they will all be copies possibly manipulated by the church, written way too late by people who never saw Jesus.
Josephus, Tacitus and Pliny are actually the best evidence you will find.
So if I apply flatearth skepticism, Why should I trust the church or the scholars? Why should I accept some manuscript as evidence of events in the first century AC, when all I have is copies made by some monks hundreds of years later?