homophobia and religious belief

i know that there are many religions that are either blatantly against the idea of homosexuality or at least hint at it in some way. but what I don't understand is the amount of importance people choose to give it. there are people who are extremely devoted to their religion, they have strong opinions as dictated by their god and I totally understand. but if I'm not a part of your religion, or even if I was and choose not to adhere to this specific belief why am I to be hated? 

at the same time, there could be many people who are religious to an extent and still have a few different opinions in certain matters. I don't understand the hate they get from their own community. to me, it feels like this hate and difference in opinion is not just based on religious belief but also people's innate character to refuse change and adapt to the current world. 

there are many beliefs that have lost their credibility over time due to constant changes and developments that communities agree on. but why is it that homosexuality isn't considered positive? why is genuine love between two partners hated so much? I'll never truly understand I suppose.

also, this is just a post for discussion and stuff, I would love to hear more about your opinions / experiences!!