Most of those will never come back, for accepting that you have been defending an abomination for your entire life is impossible and gets most people blocked. Many will go into offensive and remain forever revisionists, desperately seeking how to reinterpret things so to make them be right. Many will go into defensive and remain in silence, dealing with it by avoidance. And a very, very few will snap back into reality, recognize it's faults, and come back to you by themselves. But most of the times, none will.

That's all you can do. You can not force it, you can not work it out. You can only treat it in the exact same way as before, for this is not over.