I think it all stems from the age-old problem where religions cease becoming about the message and focus on the messenger. A century after Jesus' death, the stories of him were subject to invention-after-the-fact to feed the narrative that he was the Messiah.
Highlights include being born in Bethlehem (he was born in Nazareth), evading death at the hands of Herod (who was dead at this point), and how his ministry and miracles fulfilled ancient prophecies (which actually had nothing to do with him).
In the hands of St. Paul, St. Francis, and Roman patricians, Christianity ceased being about Jesus' message, but about Jesus himself. Henceforth, the only thing people needed to do to "be saved" was worship Jesus as the Messiah. I mean, that's a lot easier than actually practicing what he preached, right?
And, according to the Church, Jesus being the Messiah meant you had to worship him since his death somehow removed Original Sin. If you didn't, you were condemned to hell. How convenient for the Church, the self-appointed reps of Jesus, huh? No one got to heaven except through Jesus, and nobody got to Jesus except through the Church.
Quite the ironic ending coming from the people who murdered him. But hey, the Church took care of that by publishing a revisionist history that blamed the Jews (of which Jesus was one!) and making it seem like Rome was entirely innocent.
As a result, the Church committed endless atrocities, torture, genocide, conquest, imperialism, and enslavement because they were trying to "save people's souls." And all that hatred of the Jews? That led to centuries of persecution and pogroms, eventually culminating with the Holocaust.
Gandhi was DEFINITELY onto something. Christians who worship Jesus spit on him and his teachings. They are the worst kind of hypocrites and are the progeny of an institution whose history is steeped in blood and genocide - something that is still happening today!