I'm tempted to argue that, yes, it would be in the vested interest of the state to ban atheists from procreating, as well as to confiscate the children from atheist homes, and redistribute them to homes, such as Christian homes, grounded in some measure of morality or virtue.
An atheist, by mere virtue of it's own inferiority cannot be trusted around children, let alone allowed to have children of its own; for example, to an atheist, rape, murder, child molestations are not evils or moral ills, they are just alternate 'lifestyle preferences', or perhaps even a good thing.
So why on earth would we allow those to have children who can't even morally object to raping and harming children without stealing and appropriating Christian and "religious" morality?
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So sorry atheists, ultimately your children are not yours anyway, they are first and foremost the children of God Almighty. And it is therefore the natural right and duty of a God-fearing state to remove them from you, and educate them in virtue, Christianity, and morality, as opposed to degeneracy, atheism, and vice and those ills which can lead a soul in the direction of hellfire. To allow an atheist, pagan, heathen, or other Godless ilk in the company of children is a rather heinous sin which should not be allowed unchecked.