Jesus was not mentioned by Greek or Roman sources in the first 100 years. And, his first Greco-Roman reference was a passing reference. Paul also tells us very little about what Jesus specifically said. Our earliest sources are the four gospels. They are not particularly reliable, but that doesn’t mean they are useless. The Gospels are not first-hand testimony, but people reporting hearsay. They couldn’t know Jesus’s exact words.
We can look at which testimony is earlier, whether one seems to be emphasizing a bias or a message rather than just telling us what happened, to what extent different sources agree with each other, and the extent that Jesus is saying something that seems like his followers would not want him to say.
Europe was the second-fiddle Christian land until Muslims conquered the heart of Christianity. The Crusades were a delayed response to these invasions as well as continued invasions of lands controlled by Christians.
Muslims from where Algeria is now, raided and enslaved Europeans for hundreds of years. Algeria demands reparations for French colonialism, but hypocritically ignores 300 years of Algerians raiding and enslaving Europeans.
Generations of Christians went by before the idea of the Trinity was created. In much of the Bible, Jesus is treated as separate from God, but in some places, Jesus is more identified with God. The Trinity is an attempt to unify the different perspectives as one, but is not clearly spelled out in the Bible. The Biblical authors were writing from different perspectives and had different takes on Jesus.
Luke doesn’t see Jesus’s death as a sacrifice so God will forgive humans for their sins, but rather a key example of how sinful humans are–they killed God’s prophet! If you want to be forgiven, you have to turn back to God, but don’t need a sacrifice, according to Luke.
Trying to maximize their profits by limiting taxes and regulation, big corporations have funded Christian movements that preach capitalism and market fundamentalism.