No one, but Jesus, is perfect. What you would need to do to discredit their theology using their personal errors is to show that their theology produced those errors, how it did so, and that everyone who adopts those positions acquires the same personal defects, and that everyone who doesn’t adopt those positions doesn’t have those same personal defects.
Good luck with that.
And you know what it means when a Calvinist wishes you good luck...
No, I just showed you that they taught contrary to the teachings of Jesus. Their hated for the Jewish people was not a personal error, it was their flawed teaching to the church. What you should learn from knowing this about them (which you obviously already knew) is that it reveals something very wrong with their hearts (how can you say you love God who you have not seen and hate...) very, very wrong. Discern their character, it is not hidden in their many pamphlets and publications and then ask...should I really be putting so much confidence in this man? Do I want to follow this guy?