Why should people be allowed to take other people's rights away?

Short answer: They shouldn't be. A big issue is that there isn't a 100% separation of church and state, despite the fact that there is supposed to be. Take away the religious arguments that always make their way into these arguments, and you've pretty much got nothing. None of the secular arguments really hold any water.

Edit: Legalizing something doesn't mean people will be forced to do it. Gay marriage being legalized won't result in gay people forcing you to marry them, just as people aren't forced to have abortions in places in the United States where abortion is legal.

Edit 2: People have the right to liberty, freedom of expression, and equality before the law, all of which can be referenced when making an argument for allowing a number of things, most notably gay marriage.

Marriage quite obviously has a religious connection. There's also a non-religious portion of it, however, since heterosexual couples can get a marriage license from the government. As there is supposed to be a separation of church and state, and there aren't any good secular arguments against allowing gay marriage, logically there's no reason to deny homosexuals the right to marry.

Religious organizations will still be free to provide their marriage ceremonies to only those they deem worthy. Why would homosexuals want to be married by a religion that disapproves of them, anyways?

I oppose gay marriage. It goes against the word of God and being that marriage is an institution of God, then you know the rest. However, I am not about revoking or not granting rights to people to do as they please. Who are we to control what people want to do? If Betty wants to marry Sarah, then it's whatever. I don't have a heaven or hell to put them in, so why should I worry myself about taking away their right to make their own choices? God gives us free will, yet we as people don't want to allow people to have their free will. What kind of mess is that?

so you are ok with enforcing laws like gay marriage on us? so if a man wants to marry his dog to procreate with it your ok with that? this is where this goes.slippery slope there my man.

Rights that you don't have cannot be taken away.