Is it wrong that I view people with religious beliefs as being very childish? The childish part comes in the strong faith in something someone else told them.Yes! And . . .
Here's how I see it as a lifelong atheist.
Religious beliefs are based on ancient religious folklore. This folklore has no more validity than the the folklore of Santa Claus or the Easter Bunny, but since it is circulated by grownups to grownups and called religious belief, it is taken seriously by some.
While the beliefs may be childish, the people holding these beliefs are not being childish. They are expressing their faith -- in the secular sense of trust and confidence -- in those who told them these stories and asserted they are true. Trusting what they have been told by parents, friends, in some cases teachers, and religious leaders, is not childish. It's an act of faith in those they trust.
I suspect that most people of faith spend little or no time questioning their religious beliefs. Until very recently, they had almost no access to information about alternative positions, such as humanism, and atheism, therefore belief was their comfort zone. That's why some believers consider atheists who offer facts and reason in place of the superstitious tales of religious folklore to be making war on religion. (As I always say, "If there are no explosions, blood, and death, it ain't a war.)
If you wish to be the better person, then understand how believers got their beliefs and why they cling to them, and don't demean them as childish.
If you wish to promote atheism, then play to the kids in the bleachers and support freethinkers, nonbelievers, doubters, skeptics, the undecided, and the children of theists, and let them know they are not alone. Correct mistaken ideas about atheism and counter myth with reality, dogma with reason, superstition with science, sophistry with logic, ignorance with fact, and rudeness with unfailing politeness.
Consider joining the Freedom From Religion Foundation.