Athiests, do you feel compelled to love people you find unlovable?

I think it is a personality trait. Even though, as you put it, Christians are obligated to love everyone, it doesn't mean they have the capacity to do so. The same goes for atheists, they have no compulsion to love everyone and yet many atheists are openly accepting of all people. I don't think religion plays a big part in it, it just claims to. Many religious people are the most intollerant I have ever met. They will feign love and acceptance of some "undesirable" and as soon as that person walks away they start b!tching about them. I don't see how that is better than simply being hostile from the beginning, at least it is honest.