Understanding how religion works helps you as a theist - or even certain kinds of atheist - get what you need out of religion. Not everyone wants to get the same thing out of it. Some people want mysticism and some people want emotional support and some people just want to know they have a place to go every Sunday and someone who'll notice if they disappear.
None of these needs is wrong. Maybe some of them seem ridiculous, overkill, or shallow. When I was first realizing as a young Catholic that what I needed from religion was that mysticism and a more... hands on deity than I'd found in Jesus, I thought the "shallow" religion of my fellow parishioners was a sham. Eventually, though, I grew out of using the word "sheeple" and understood that they were happy. (Well, okay, some of them are happy. But you get the idea.)
If somebody is happy with themselves and their religion, that's great. They've got it handled. I'm not writing this for them, though. If you're here, if you're reading this as a part of the search for something in yourself, you're my audience. There's nothing wrong with admitting that, like Bono, you still haven't found what you're looking for. In fact, there's a version of that song recorded in concert like a decade later where he adds "and I hope I never find it!"
Most of the time, I find I agree with Bono. There is a lot of value in the journey, with or without a destination. Yes, sometimes I get tired. Sometimes I'm envious of people who get their needs fulfilled by showing up once a week. But the majority of the time, I'm like a metaphysical shark. If I'm not moving, I'm drowning.
I've studied a lot of religions and magical styles. I wouldn't call myself an expert by any means, but I've done a lot of reading and practice. I'll try anything once, and I've tried lots of things more than once. I keep what works.
Understanding how religion works and what you need out of it lets you make solid choices when you're going into that practice. When I build a religion from scratch, I can make sure it addresses my needs. Some people will tell you that what you want or need doesn't matter. If there is a god picking you up by the scruff of your neck, that may be the case, but even if a god reaches out to you, he or she is not necessarily going to control every part of your religious life, and that's okay.