Let's use the more specific example that you have given which applies only to religion.
You are making the claim that if God allows a child to be born into a family with a certain religion, then God must not have a problem with that religion or He would not allow the child to be born into a family of that religion.
Is this your point? Please clarify where I am mistating your viewpoint so that I may understand it clearly enough to test it.
Most monotheists beleive that it is only God who can endow the body with the soul. So if God is opposed to non-monotheistic religions, why would he send souls into babies that he knows are going to be raised as pagans?