An all-powerful God could have created free beings who always choose good

Why the argument is clever

Mackie's point is sharp. A free person could choose good on any occasion. So it seems possible that a free person might choose good on every occasion, and it seems possible that every free person might. If that's possible, an all-powerful God could create such a world. The existence of evil would then show God isn't both good and omnipotent. This is the classic logical problem of evil.

Plantinga's answer

Alvin Plantinga responded in God, Freedom, and Evil (1974) with what's now called the free will defence. His point: if people are truly free, then whether they choose good or evil is up to them, not God. God can create free beings, but he can't make them freely do good. That would be a contradiction, like a square circle. Omnipotence means the power to do anything logically possible, not the power to do nonsense.

So it's possible that in every world God could create with free creatures, some of them would freely choose evil. If so, God couldn't create a world with real freedom and no evil. Most philosophers, including many atheists, now agree that Plantinga's defence shows there is no strict logical contradiction between God and evil. Debate has largely moved to the evidential problem.

Why freedom is worth it

Why would God value freedom so highly? Because love requires it. A person who couldn't do otherwise couldn't really love, choose to be kind, or grow in character. C.S. Lewis wrote in Mere Christianity that free will, though it makes evil possible, is also the only thing that makes love, goodness or joy worth having. A world of robots that always do the right thing would be safe, but it wouldn't contain love in the full sense.

What about heaven?

A natural follow-up: if people in heaven freely choose good forever, why couldn't God make that world from the start? One common answer is that heaven's freedom is the fruit of character formed through real choices in this life. People become the kind of people who freely love good, through a process that requires the possibility of failure.

A fair concession

The free will defence explains moral evil better than natural evil (see Natural disasters aren't caused by free will). It also shows only that God and evil are consistent, not that God's actual reasons are known.

How to explain this to a friend

An everyday illustration helps here. You could program a phone to say "I love you" every morning, but no one would call that love. Love only counts if it could have been withheld. If a friend asks why God didn't just make everyone good, ask whether a world of guaranteed goodness would still contain real love, kindness or courage. That often reframes the question in a way that feels intuitive rather than technical.

The bottom line

God can't create free beings and guarantee their choices at the same time, any more than he can make a married bachelor. If love and freedom are worth having, a world where evil is possible may be the price. Explore more on The problem of evil.