So in fact religious people who think homosexuality is a sin must believe homosexuality is a choice.

Granted, the official doctrine of the Vatican is now that homosexuals are not sinners, but that homosexual acts are a sin.

But "although the particular inclination of the homosexual person is not a sin, it is a more or less strong tendency ordered towards an intrinsic moral evil; and thus the inclination itself must be seen as an objective disorder."

It is unclear to me how they can reconcile that with the following question: if that is a disorder, then why did god inflict to people a disorder that makes them prone to sin?