Don't you worry that if Christians are allowed to adopt that they will abuse their kids?

Well reality shows us that some children who get adopted DO get abused, and sometimes killed. Perhaps no one should adopt and gays should run orphanages. (Okay, I'm being facetious. I don't see any reason why gays shouldn't be allowed to adopt as long as their relationship is stable and loving and their situation is good enough to care properly for the children.)