Yannie
The trouble is, you think you have time
Except.....when people make a statement that's open for scientific scrutiny Such as '' Homosexuality is a choice''. Instead they should say I believe that ''Homosexuality is immoral and goes against my religious convictions''. I don't think anyone would have a problem with that second statement because its not for a debate. The former leads to a debate in which both parties have to back up their claims with evidence and a holy scripture is not evidence.
Whether homosexuality is due to genetics...? No one really knows though... It's like saying that intelligence is entirely due to genetics.. Although it's partially true that genetics may influence one's intelligence. it's not entirely right. The same goes with homosexuality, i think. Those scientists who claim that homosexuals are genetically predisposed to it, are not completely correct and other factors play a bigger role. But you'd have to be utterly naive and intellectually dishonest to think that homosexuality is solely due to environmental factors. Because it doesn't explain why there are homosexuals in a religious environment where homosexuality is considered immoral and is punishable by death.
Yes one can argue that homosexuality is immoral because its against one moral belief system. Also , science have not found a gene that link with homosexuality behavior. So therefore you cannot argue that homosexuality has a genetic link.