Sorry to say it, but (most of) you went full retard in this thread (which was expected).
1) If you are not Christian (or generally not part of religion) why do you care what they say is sin. I mean, if you are not Christian in this case, why do you care if Christians think abortion is sin. If you feel like it isn't, just do it. If you feel it is, don't. Even if you are Christian and you don't think it's not sin, well do it. And even if you are Christian and you think it is sin, you can still do it, right? I mean, we all make sins we are aware of. Sure some weight more some less, but that's reality. If Church says it's sin, it doesn't mean all Christians will obey it. It is wrong of Christians (and other religions) when they try to force their religious laws into country laws, but that is something natural to humans -> they try to shape world as they want it. If i like icecream i'd want to be able to eat icecream anywhere anytime, no? If i hate walking i'll make something that will help me move without walking. Now i made it i'll want others to use it, i'll want to show them how i do things i do. It's same with religion.
2) Homosexuality is not something that exists last few years. It always existed. It is, in a way, protection of human race, meaning, if whole gender disappeared somehow or something happened to it, humans (as well as animals) that remain have possibilty of changing gender through natural process to continue their race, to be able to reproduce. While most humans (animals) are male/female, there exist those who are something between -> those who will first mutate in those conditions. While conditions are stabile, those people will not mutate, but will have bit different personality -> they will be attracted by same gender, and you get homosexuality. For most of the time, people were aware those people exist and it was just ok. Nobody said anything about them, since there was no need. I mean, gay (lets take male for example) didn't bother women so they (women) didn't care. Only males that had relationship with gays were gays. So they stayed together, it was closed group. As they couldn't have children, it stayed like that. Two gays lived together, and eventualy died. We also know of gays who were married (with woman) and had children, but were attracted to males and had (often sexless) intimate relationship with other man. To return on topic, they lived their lives like all people did. They were different but still same in so many ways. Now we have new generation of gays. This are not people who were born like that in most cases, but somehow ended up becoming homosexual. Mostly because of living situation, maybe parents wanted girl, got boy and raised him like girl. Or maybe some girl terribly hurt feelings of boy, which resulted in him hating whole gender, and becoming gay. Maybe it was person living in prison or anywhere without opposite sex and had to become homosexual. Those people often aimed on "normal" people for they boyfriends, and turned them to homosexuality. It would still be ok, if they didn't start asking for their "rights". And that was simply stupid, because they already had rights of all other humans (in most of countries most of times). They were allowed to vote, work, kiss, hug, live together, go to school whatever. There might have been people who discriminated them, but lets face reality, there will always be people who won't respect other people based on anything. Profesor might hate gay, doctor can hate ginger, policeman can hate black person, trainer might hate poor person, it happens. To return to point again, i mind their need to express themselfs as gay. If you are gay, be gay and it's ok, don't shout "I'm gay!" on road. I am not screaming "I'm nerd!" or "I study physics!" or "I need to pee!" or whatever.
When i already touched 2/3rd of title, i'll touch last one as well
3) Idoelogy is basicaly same thing as religion. Difference is that religion looks to spiritual things, while ideology on material things (generally, not always). As human has both soul and body, he seeks something which will show him how to live (both for soul and body). Religon will gather people with similar souls, similar thoughts about purpose of life, what happens after death and "why"s. Idology will gather people (often) of similary body/race/nation, similar thougths about how to live life, and how we came to life, and others "how"s. Ideology is religion we can understand actually, what our reason and experience say. As it is in core same thing, it should be treated same way in everything. You either like it and support it, or don't and you fight against it. Both die without support of people, as that is all they have: people who do what they say.
We can say that religion or ideology is "good" or "bad", but we all know how relative this two words are. Which makes all religions and ideologies equal in every aspect. Power of them is determined by number and power of people who follow them.
And just a bit about science: as everything made by humans it has errors.
