I'm not sure if something is missing. If it's anything, it's the ability to think clearly and independently. As a child I went to Sunday school, but one day I just got tired of it and asked if I could stop going, and my mother said "Sure." So, I stopped going. This didn't prevent me from believing in god, but what it did do was, over time, allow me to realize how ridiculous religion can be.
Over the course of time that Humans have been on this planet, Earth, there have been COUNTLESS amounts of religions. Most of the time, a person is brought up in a religion against their will, unknowingly accepting it without having a chance to fight or feel the need to exercise their ability to choose on their own. Some people will profess that their child was given a choice of what they want to believe in as a kid, but this is very hard to determine. A child will naturally want to copy the actions of their role models. If the person they look up to goes to church every Sunday, or bows to Mecca five times a day, they will want to do that as well, even if they are asked if they don’t want to. Once that seed has been planted and starts to grow, it can be hard to stop. It's like an addiction, almost. Without knowing if there is a god, you get withdrawal and begin to undergo a mental change that can be painful and hard to let go of, or at least worrying to you, not to mention your loved ones who still probably believe in god and are unwilling to accept your belief. I can’t say that last sentence stands true for me because my family knows what I believe, and we’re all very open and have our own individual beliefs, just as any person should be able to.
For all practical reasons, I am agnostic. At this point in time it is impossible for us to determine whether god is real or not, regardless of what some people say (on both sides). It is impossible to prove or disprove with any amount of scientific/tangible accuracy the existence of god. The universe is a very mysterious and confusing place, but over the centuries us humans have been doing the best we can to unravel it. We get further everyday, but like a point on an expanding balloon, the end seems to drift away in all directions, no matter where you are on it.