Praise God that the Gospel does not merely forgive us of our sin, but it grants us a new identity. It gives us an identity that is not defined by who we are, or what we fight for, but is freely given on account of who Jesus is. It frees a person to love those we disagree with, pray for our enemies, and compel even the vilest of sinners that Jesus can change them, every single part of them. Because it did exactly that to us, and continues to do so on a daily basis.
So the question is not “so what if homosexuality is a choice?”, but rather “even if it is not a choice, will you let Jesus change you?”