This assumption comes from a lack of understanding of a few scriptures, confusion of gender conflicts with sexual misconduct, fear of variance, or simple prejudice. These all may be good arguments, but I fear we use them prematurely. These should come after we get to know the other person and not before. Even then, they should be used only in the context of loving discussion and not in that of a battle. The ultimate proof of our Christianity to the Christian as well as the unbeliever is our love.
Love really is the final apologetic.
It is hard to attack someone who will not attack back. It is hard to remain angry at someone who will not return that anger. It means loving those who hate me. It means doing good to those who try to do evil to me. It means taking some hits and not returning the same.