To engineer (either or both) "kill switches" and fertility switches directly into human DNA such that they can terminate life whenever they want and/or terminate genetic lines when they deem them "unsuccessful"?
To me if nothing else proves that there's the devil in this world, this is it.
And if there's the devil, then there is God.
The heartiest of the saints are the ones born in the latter days before Christ comes back. It's all a matter of whether you pick up the armor God gave you or not and fulfill your duty.