I’m flabbergasted that you’d suggest that the death of a child’s father could “make the family stronger.” Except in those circumstances where the parent is a complete monster, the death of a parent is a hideous blow to the family.
It doesn’t mean that the family cannot find happiness again, and if the surviving parent marries a wonderful person, the family may be great, but that doesn’t change the fact that the death of a parent is a profound loss, and a wound.
People have been speaking of adoption. I think adoption’s wonderful, and I’d never say that a family with adopted children isn’t a “real” family. My adopted relatives are my relatives. However, adoption, too is built on loss. Read the stories of adult adoptees to see that they can experience some very complicated feelings because they were not raised by their biological mother and father.
Two gay men pretending to both be the father of a child can love the child dearly, and think of that child as their own, and treat the child very well, but at least one of those men is not the father of the child. And that child is, at the very least, missing a mother. This is a loss.
Single parents raising kids on their own may be doing a wonderful job and giving their kids great lives. But the missing parent is still a loss, even if there are excellent reasons for that missing parent not being in the child’s lives. A person is not living up to the responsibilities of parenthood for some reason or another is something to mourn.
God declares that families are to be formed thus: A man shall leave his father and mother and cleave to his wife, and the two shall become one flesh.
(edited to remove unnecessary “of the fact that” x 2)