Centuries before Constantine, in the book of Acts the story is told of an early--some believe the first Gentile--convert to Christianity ... an Ethiopian eunuch who was baptized by Philip. The Coptic Christians of Ethiopia do not share the same western European history you have described. Not that I believe in Christianity or Jesus, but there are other "unvarnished" traditions out there which have survived.
I have wondered about this myself. Not so much specifically what is posted in the meme, but the mere fact that Christianity is so deeply rooted in racism. But then again, I guess the reason we have a bazillion different "Christian" philosophies out there, it seems most simply choose to make it what they want it to be.