Perhaps a word of explanation would help. If you slip a duck egg into a hen's nest, she will hatch it and allow the duckling to skitter around the barnyard with her natural-born brood. That creates one frantic mom. The hen, fearing for her adopted baby's welfare, will panic. The whole circus proves a hypothesis.
Ducks ultimately act like ducks and chickens act like chickens.
Both are human beings, of course, but spiritually they are as alike as apples and Pontiacs. Christians shouldn't go around strutting as if they're better than anyone else. God caused the change in our lives. He made the amazing transformation. We can get confused at times.