Billboard proclaims "Nobody is born gay"

[Esquilax]

Being homosexual is a deficiency?

Yes. It is contrary to the natural order, since the defining desires of homosexuality are directed away from the proper use of human sexuality.

I do have one thought on this matter, which is that you've made the usual mistake that christians tend to on this issue, by baselessly asserting that the "proper" use for human sexuality is its most simplistic mechanical component, and this simply is not the case.

Procreation is but one use of sex, a big one for the animal kingdom of which we are a part, but it isn't the only use that sex has in human beings. It also plays a part in the formation and strengthening of romantic relationships without bringing procreation into the equation, something that even the most conservative of christians understand, given just how much they build up sex as a component of a relationship, and what a big deal they make out of it. Taking sex in that light, the properly understood light of all the purposes sex serves, then homosexuality is entirely within the purview of a "proper" view of human sexuality.

You're probably tempted to dismiss this as immaterial, appealing to some undemonstrated final ultimate cause of sex, but why? Why do you get to dictate what proper sexuality is, even where you contradict our knowledge of biology to do it?