>What's significant though is the PREVALENT opinion. 100% of my religious friends want and have kids, while the majority of my secular friends do not.

Do all of your religious friends subscribe to the same religion?

If so, does this religion proscribe having children and raising families as a necessary, or desired, component of the faith or community?

Because you could be confusing religion and culture here. Secular values often abrogate traditional gender and sexual norms, so secular people may not feel compelled to "be fruitful and multiply." I wouldn't ascribe that to lack of religion per se so much as not being affected by the same cultural pressures. After all, plenty of theists are essentially forced into marriage and children because it's what's expected, not because it's what they want.

Putting aside the question of whether your own experiences hold for the general population, you must consider why these opinions are so prevalent, either way. One might argue that religion doesn't teach 'values' so much as 'roles', and so people feel they must do these things, not for any significance or with little thought to possible negative repercussions, but simply because... well, that's just what you do, right? Find a partner, have kids, go to church. That's the lifestyle religion teaches. One might also argue that secular people aren't as intent on having kids because they're more willing to accept different lifestyles.

For what it's worth, krapp's comment is better written but is what I'm talking about here.