Often times you will hear unbelievers demand extra-biblical sources to validate the Christian narrative. However, this is usually based off of two incorrect assumptions.
First, unbelievers assume the Bible is one book written by one author when in reality, it is made up of 66 books written by around 35-40 different authors over thousands of years. Unbelievers point to the Bible as a whole demanding more sources but they already have 35-40 different sources.
The second assumption is that the sourcing of the Bible must be discounted because it was biased towards Christianity. It is important to grasp what they are demanding here. They are demanding that the sources are unreliable because they happened to write in favor of the Christian narrative.
Both of these premises are not pursued with any other ancient writings. These demands by unbelievers are exclusive to the Bible. They are holding separate standards for evidence that other historical events occurred than those pieces of evidence that the events of the Bible occurred. In fact, they are attempting to create a high enough bar that no matter what level you offered, they would come back and say “we need more”.
So this argument that says extra-bible documentation to validate the biblical narrative is simply one not worth engaging in because it would always be about changing goal posts. Nonetheless, we will tackle the extra-biblical evidence just for the sake of showing it is out there. Are there extra-bible sources? You bet.