If a religion treats gay individuals or relationships as lesser than straight ones, the religion is anti-gay.
Or, on an individual level: If someone interprets their own religion as requiring them to diminish or exclude gay people, their religious interpretation is anti-gay.
Thinking and acting based on an anti-gay belief makes a person anti-gay. If a person says "I'm not anti-gay; this is just my religious belief," they're attempting to detach themselves from their own opinions (belief, culture, habit, etc.), and they're blaming this "religious belief" as if it existed separately from them. It doesn't. We have responsibility for our own understandings of our own religions — including who and what we choose not to see, be it a "religious" choice. Our beliefs may be acquired unconsciously or at a young age and may be hard to change, but nevertheless, we're accountable for what we say and do.
If people deserve credit for good values and character traits that their religion produces in their behavior — like being patient, kind, organized, hopeful, and so forth — they can also be held accountable for how they're linked to their religion's anti-gay teachings.
If a person does not want to be anti-gay, they should question and adjust their anti-gay religious beliefs. The process of reexamination has to involve listening to a variety of perspectives of gay people — and not just the minority who will smile and tell you that the reexamination isn't necessary, that it's OK to be anti-gay, that nothing really hurts them or any gay person. The reexamination will require understanding how, regardless of the speaker/doer's intentions, anti-gay words and actions can harm at least some (if not all) gay people.
The problem won't dissolve into a statement like religion-is-whatever-it-is-and-I-don't-wish-gay-people-ill. Our assumptions are value-laden, and our choices can harm others. We aren't always conscious of it, but we can become conscious of it.
As long as someone chooses not to do that reexamination, especially after it's pointed out to them, they're choosing to be anti-gay.
