I'm not the slightest bit religious, but I have way more respect for people who are and leave others alone instead of the assholes who think criticizing them is somehow enlightening.
Christians (and most other major religions) by their very nature are proselytizers. They do not "leave others alone." They seek to control or sway powers to further their own irrational goals. Any gay American can tell you as much.
I hate to go there, but think of the children. How many children are raised and taught from day one that service to their parents' religion is paramount? That any questioning of their beliefs is a hostile force designed to test their resolve? That BILLIONS of people around the earth are WRONG in their own (equally idiotic) beliefs? That it is permissible to accept things as truth in total absence of evidence, in denial of the very foundation of all practical human advancement throughout history?
To say that religion and its practitioners should be left alone is to say a bulging tumor should be left to its wholly destructive malignance. Now, I'm not going to get militant and start or join a crusade because the tools at my disposal (rational thought, secular ideology, an open mind) are wildly ineffective when wielded. It is entirely impossible to engage in discourse with zealots.