The problem of evil is one classic argument against the Christian God. This is often stated as:
If this argument is correct, it would mean the God of the Bible isn’t the god of reality. However, Augustine offered a compelling alternative syllogism:
The problem then comes down to: what is evil? Augustine answered: “Evil has no positive nature; but the loss of good has received the name ‘evil.'” In other words, evil isn’t a thing in and of itself; it is the lack of goodness.
In an explanation of this line of thinking, Greg Koukl offered a couple comparative analogies. First, while we may say things are cold or hot, technically there is no such thing as cold; only a lack of heat. Likewise, we call the air in the centre of a donut a “donut hole”; yet it simply the space where the donut isn’t.
He sums it up like this: “So donut holes don’t exist; they’re just the absence of donut. Shadows don’t exist; they’re just the absence of light. And evil doesn’t exist; it’s just the absence of good.”
Therefore, evil is not a proof against the existence of the God of the Bible.