>but which of the two has really caused more harm for humanity?

I take it you would like to compare against the whole of the Vatican's existence, and not against just the whole of Peter Thiel's adulthood?

If you like, we could compare a single Thiel adulthood to individual randomly chosen lives of popes. The average pope has a lot more blood on their hands. Both are bad, but one has caused more harm to humanity no matter which way you slice it. To argue that a single heretic is worse than the whole catholic church rings pretty silly to me. The best would be if they were to both destroy each other, but let's be real and acknowledge that Peter Thiel is going to die and become irrelevant long before the catholic church, which may very well continue on for another two thousand years for all we know.