A friend of mine the other day said logic is useless when talking about God. I disagree.
I've been a fan of William Lane Craig for a year or so, and I'm sure many of you know who he is, a very popular Christian apologetic. (Unfortunately, he's a Trinnie

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Atheists often use the problem of evil to supposedly prove that God could not exist, as he wouldn't allow such things.
Per one of his debates, see the below assertions.
(i) If God does not exist, objective moral values do not exist. If there is no God, moral values are either socio-biological by-products or just expressions of personal preference.
(ii) Evil exists. That's the premise of the atheist. There is real evil in the world.
(iii) Therefore, objective values do exist. Some things are really wrong.
(iv) Therefore, God exists.