Well I'm going to start with:
1. You don't need to mention 'God' in anyways to say if homosexuality is right or wrong, because all existence and 'nature' and the order on how every living thing works, tells us that they are not one of the norm or that they are a 'gender', basically homosexuality is a sexual preference and nothing else, also i do believe that it can be a mental irregularity due to the fact that sexual attractions first happens in a mental chemical pattern, if you do a little research about how the attraction occurs in the mind then you may understand a little about the matter, also there are drugs that may enhance these 'homosexual' urges, the most common known is 'ecstasy'.
2. Even though I believe it is wrong, there is something that i can not over look, and that is 'happiness', humans are a always in search of 'happiness' and happiness is relative from individual to individual everyone has their own 'logic' and 'reason', thus giving the meaning "what is right for you is not right for others", when we fail to understand, 'Why?' do people do what they do, one can say that most do it because they are searching for their own place or 'happiness', I always say if it makes you feel happy then I think that is best for you.
3. Now I would like to give my opinion in fully about Homosexuality, like stated previously 'Homosexuality' is a type of sexual preference, just like your own or my own 'fetishes' they are basic preference, now how is that they have decided to be a 'homosexual'? Well for my understanding I for one believe that 'Environment' is one of a the causes, well for example, let's take myself I in some factors have a more 'feminine' aspect(by no means I'm saying that I am homosexual), why? well in my family, I grew up with practically all females around me(Mom, My two sisters, mostly all of my cousins are female) so practically you tend to pick up traits that may confuse you(as the person) and others in to thinking that you are homosexual, but even still with all that feminization, I am still attracted to females, other cause can include sexual abuse and other more like 'brainwashing', anyways as for the concluding, I will say that it is wrong, but I will respect their decision and their own pursuit of happiness.
Well those are my thoughts about 'Homosexuality' and I also am a non-believer, but don't pile me up with the rest that don't wish to learn about the other, I say we should learn from both sides and not balantly point the finger at each other, because like stated previously in your 'world'(Mind and/or life), your logic, your beliefs, your whole way of reasoning means nothing in other peoples 'world', but if we stop and listen and try to understand then, maybe we can really know what it is to be human.
Well that is all. Class dismissed!