One of the most common objections to theist claims is the so-called "problem of evil." The argument goes: An all-good, all-knowing God would not allow evil to exist in a world of His creation. Evil does exist, therefor an all-good, all-knowing God cannot exist. This is a big sticking point for a lot of people, though I've always had a hard time understanding why; it seems to be a very shallow way of looking at the subjects of good and evil, and the mind of God. Libertarians, however, should have an easier time grappling with this issue, with their understanding of unintended consequences and social complexity. I'll attempt here, then, to resolve this problem of evil using libertarian language.
There are two components to the problem of evil. The first, evils that occur due to human choice, is relatively easy to handle. The second, evils that occur outside of human control, is a bit more difficult. I'll give the first a brief treatment, and then move on to the second.
A central tenet of Christian theology is the doctrine of free will. God gave man the ability to choose between good and evil. If God simply wanted robots with no ability to sin, then their apparent "goodness" would have no value. Out of His love, he gave us the ability to choose to love him or not, because genuine love can only be given freely, not commanded or forced. Most libertarians also believe in free will. If we did not, it would be meaningless to judge an action as ethically right or wrong, and it would make no sense to punish a murderer or thief. So if we take free will as our premise, it's clear why God would allow evil committed by human beings. To disallow it would violate the free will that is necessary for moral acts and choices to even be possible. Mass murder, genocide, slavery, and taxation are all evils committed by mankind exercising their free will, and cannot be "blamed" on God or taken as evidence of His non-existence.
But what about the second component of the problem of evil, that is, evils that occur outside of human choice? This requires a more in depth explanation, and this is where I think libertarians in particular are better equipped to understand to subtlety of the answer.
For many of us, when we begin to learn libertarian theory and economics in particular, it is like putting glasses on a person with blurry vision. Suddenly, the world is brought into focus, and things that were obscured or not seen at all are viewed with clarity. Some things that at first glance may seem indefensible, even evil, can be seen in an entirely different light.
Take, for instance, child labor. People living in a modern industrialized society can easily say that no child should be made to work, and only a bad parent would require their child to do so. But even a cursory understanding of economics, or simply the idea of cause and effect, shows us that bans on child labor in third world nations results in starvation for the child and their family or child prostitution. The child doesn't work because their parents are cruel; they work because they have no better options.
Or consider the ruthless dictator. It's easy enough to hear about atrocities committed against his own subjects and declare that "So-and-So must go!" But a quick glance at even recent history will show what often comes of such interventionism: the dictator will most likely be replaced by either a worse dictator or a situation of rival factions warring over who will fill the power vacuum. Neither outcome works out very well for the citizenry that the intervention was meant to help.
As we gain understanding of cause and effect in the world, we are able to take a wider view. We can see that some situations or events which may on their face appear to be clear evils should not necessarily be artificially altered, lest we cause a greater evil. If we, with our limited minds, can see these phenomena, how much more would be understood by an infinite mind?
In the examples of child labor and the dictator, we are considering situations that we, as outside observers, did not directly bring about, but into which we have the potential to intervene. Taking a broader perspective, we can conclude that, although an intervention may be possible, it is wiser in the long run to take a hands-off approach. (Here, of course, I'm referring to political intervention and the use of force; this is not to suggest that individual voluntary action such as charity is unwise or harmful in these situations.) Similarly, in the case of such things as natural disasters, disease and famine, the existence of which humans have little control (to the extent that they are naturally occurring and not the result of human action), and it is difficult if not impossible to see any good that may come of them, it may be that God, while He has the ability to intervene and prevent them, chooses to allow them due to his infinite perspective and understanding of all cause and effect relationships.
In Christian apologetics, it's often said that God will allow certain evils in order to bring about a greater good. This may not initially seem like a very good answer, but the libertarian himself will make use of the same sort of reasoning to argue against intervention in apparent evils in this world.
If the cause of all existence can see the entirety of space and time, in full and perfect understanding of it, then it is not unreasonable to assume that certain events that seem to us, in our minuscule understanding, to be incomprehensible evils, may be allowed by an infinite mind to accomplish a fundamentally good end.
It is impossible for mere mortals to unravel the entire knot of human history to show why each event occurs in the grand scheme of things. But the fact that even we, as we gain understanding and wisdom, can unravel small knots, shows that for a being of infinite understanding and wisdom, and perfect knowledge of all events, the large knot would be no knot at all. It would be, rather, the image of a grand and infinitely complex design. Our inability to comprehend it all in this life is simply not a strong argument against the existence of God.
