Someone might ask, “Adoption, of course, does not provide children with both biological parents either, but we allow this. Why?” Simply because adoption is a heroic effort of a couple to provide a mother and father and loving home for a child who does not have this. As such, it is an exceptional act, and no one is saying that adoption is just as good for a child as living with both biological parents, assuming that they could provide a good home. Adoption is a wonderful and selfless act of charity, but it can never become a social norm, as same-sex advocates are arguing for same-sex families, which is largely a selfish act. It wouldn’t be a good thing for everyone to raise everyone else’s child, just as it wouldn’t be a good thing for every child to be separated from his or her biological parents and placed in a same-sex home. Biological mothers and fathers raising their own biological children is the ideal. When the idea is not attainable for some reason, adoption by married mothers and fathers is a loving and heroic alternative. It is the next-best thing. Same-sex parenting is not.
Glenn T. Stanton and Dr. Bill Maier, “Marriage on Trial: The Case Against Same-Sex Marriage and Parenting,” pg.85 footnote