Francis Spufford has some advice for what to do with the worst things Christians have done.
When people bring up the Inquisition, and the Crusades, and book-burning, and the various other big items in the great Christian roll-call of failure, I tend to go: yes. Because we did wrong, repeatedly, and there are particular ways in which Christianity has been liable to falling into error, and because we’re human we’ve done it over and over again. We should have the humility just to agree to the wrongs done in Christian history, and we don’t then get to speed onwards to the point where we go “yes, but …” and insist on the good stuff. Because the good stuff doesn’t balance out the bad stuff – the good stuff is true as well, but the bad stuff was sins. And what you do with a sin is you confess it. And you don’t get to tell other people that it’s time to talk about other things. If you’ve confessed to them, you have to just sit on your hands and wait for them to decide that it’s time to talk about other things.