The problem of evil constituted a serious challenge to theism ever since the Abrahamic prophets have introduced the notion of an omnipotent, omniscient, and perfectly good God. The challenge is to explain how an all-powerful, all-good God could allow such a vast amount of evils in the world. We can provide a long list of paradigmatic evils that history has recorded and also surrounded our world (Evidential Problem of Evil). However, Alvin Plantinga, in his book, The Nature of Necessity, defends the logical consistency of theism and claims that believing in an omniscient, omnipotent, and all-good God is consistent with acknowledging the existence of evil. As he puts it, the two premises that
(1) God exists and is omnipotent, omniscient, and perfectly good.
(2) Evil exists.
are not inconsistent. Plantinga maintains that conjunction of propositions (1) and (2) is not necessarily false and claims that he has proven that (1) and (2) are in fact consistent. “The resources of logic alone do not enable us to deduce an explicit contradiction from their conjunction. But then presumably the atheologian—he who offers arguments against the existence of God—never meant to hold that there was a formal contradiction here; he meant instead that the conjunction of these two propositions is necessarily false, false in all possible worlds” (The Nature of Necessity 165). If an atheologian is to prove that the claim of inconsistency in the theist’s account, must therefore, needs to posit a proposition that is both necessary and in conjunction with (1) and (2) constitutes a contradiction. Plantinga has argued that finding such a premise is extremely difficult.
Plantinga’s Proof of consistency
Plantinga, to show that it is possible for (1) and (2) both to be true, therefore, consistent, appeals to the notion of free will. Plantinga believes that the free will defender needs to find a proposition that is consistent with (1) and at the same time entails (2). That proposition itself does not need to be true. All it needs is that to be consistent with the proposition (1) God exists, and is omnipotent, omniscient, all perfectly good and at the same time, it entails the existence of evil. That proposition with the above two conditions is, “… it is possible that God could not have created a universe containing moral good (or as much moral good as this one contains) without creating one containing moral evil” (167). To him, God created the world within the constraints of necessities. For, “God, though omnipotent, could not have created just any possible world he pleased” (168). In fact, this latter point is crucial for his defense of free will. God could not have given us free will and at the same time made us freely to do good things or refrained us from evil things. If he did, we would not have free will. It is a logical impossibility to think that free will is consistent with preventing all evil doing. In fact, the existing evil in the world is a byproduct or undesirable consequences of our free will.
Despite what Leibniz believes, to Plantinga, God in the moments of creation did not have a whole range of choices of possible worlds from which he could have chosen the best possible world. Rather, he merely created contingent things such as heavens, mountains, animals, and humans. God did not create necessary things, such as “himself, or numbers, propositions, properties, or state of affairs” (169). Those necessary things always have existed. To create something means to have a beginning, while the necessary things have no beginning in time. They are eternal entities. “God has created Socrates, but actualized the state of affairs consisting in the latter’s existence” (169). Therefore, it is misleading to believe that God has created everything. To say that x is created, it is to say that there was a time that x did not exist. Numbers as non-created things always existed so as God himself and his attributes. God did not even actualize non-creatable things. “So if we speak of God as actualizing a, we should not think of him as actualizing every state of affairs a includes. But perhaps we may say that he actualizes every contingent state of affairs included in a; and perhaps we may say that God can actualize a given possible world W only if he can actualize every contingent state of affairs W includes” (169). After these distinctions, he asks whether an omnipotent God could actualize any possible world that he pleases?
Obviously, his answer is no. Therefore, he concludes that God could not create a morally free agent without giving them ability to do evils. However, the value of having free will and being able to do evil is greater than if we were created as individuals with no freedom and no ability to do evils. The question is that, even if we grant Plantinga that evils in the world are, if fact, necessary evils that even God could not eliminate, then is the question of evil settled? I doubt it. I think the problem of evil, in Plantinga’s account, is not settled, but it is moved from the level of necessities to the level of contingencies. Therefore, one may ask, is there any unnecessary evil in the realm of actualization that God could have eliminated or can eliminate, but he did or does not? I will answer this question in the next section.
I believe we can modify Mackie’s thesis of logical inconsistency of the theist’s account of evil so that it shows the inadequacy of Plantinga’s solution. To Mackie, (P) a perfectly good God always would eliminate evils as much as he could and (Q) there is no limit to what an omnipotent God can do. Unlike Plantinga, Mackie believes that (P) and (Q) are both necessary. However, to Plantinga, a perfectly good God can sometimes permit evil if it is morally justifiable, like in the case of free will, and there is, in fact, a limit to what God could or could not do. Therefore, Plantinga maintains, there is no inconsistency between (1) and (2). However, in light of Plantinga’s critique of Mackie in The Nature of Necessity, one can reintroduce (P) and (Q), so it might constitute a logical inconsistency between (1) and (2).
One may agree with Plantinga that (P) is not necessary. Unlike what (P) states, God may permit evils either if there is a moral justification for it, therefore, not-(P) or God could not create whatever state of affairs that he pleased, therefore, not-(Q). A perfectly good God could prevent contingent evils as much as he can (Pa), and there are no limits in God’s power to actualize contingent things (Qa). If so, the problem for Plantinga is that there are some contingent evils that God could have prevented, but he did not. Therefore, I think in light of (Pa) and (Qa), (1) and (2) constitute a contradiction.
Is there any evil in the realm of contingencies that God could have avoided, but He has not? We can grant Plantinga that God could not have actualized every logically possible world; even doing so, the question of evil has not been settled. Plantinga’s notion of creation as actualization limits God’s creative power to the realm of contingencies, which is the realm that could had been different than it has been actualized. For example, God could had created a world in which Donald Trump did not run for presidency, or if created him, instead of having locker room talks, he would had read more useful books. However, since the world has been actualized in the existing way, where Donald Trump has run for presidency, even God cannot change it. Changing the past is a logical impossibility and God, to Plantinga, cannot make impossibilities possible. An omnipotent God cannot actualize every possible world, let alone the best possible world.
So the question is that, “is there any evil that does not emerge from necessities but from contingencies?” Creating certain individuals is within the power of God and by refraining from creating certain people, he would not violate any necessity. God could refrain from creating Hitler, for instance, or people like him who made people suffer unnecessarily, but he did not. In the time of creating him, God, due to his foreknowledge, knew about what crimes he would commit. So the question is that why did God create Hitler? God not only created Hitler, but put him in a situation that he committed horrendous evil. God could have created millions of people that he has not. There was no necessity to create certain people whom God knew would use their free will to commit gratuitous or horrendous evils. So the existence of evil is not necessarily the existence of those evils that spring from necessities, if we accept Plantinga’s account of free will, but the problem is the existence of horrendous evils that emerged in the realm of contingencies, evils that could be avoided by an omnipotent God that Plantinga believes has a foreknowledge. If so, then (1) and (2), unlike what Plantinga states, are not consistent.
My position is not same as Paul Helm’s when he states, “Any agent who freely and knowingly sets up a deterministic process with a certain outcome must be responsible for that outcome, but on the level of contingencies.” Plantinga would agree with Helm that God set up a deterministic process. Plantinga would reply to Helm that what he calls “a deterministic process” might be only “state of affairs” that God did and could not create but merely actualized it, and since God has not created this state of affairs, he is not responsible for the outcome of this state of affairs either. However, I think this problem exist for Plantinga, who does not argue for determinism, but on the different level. Even if we agree with Plantinga about free will, still it does not explain the existence of evil that is not caused from necessities, but from contingencies. It is compatible with human free will if God refrains from creating some evil agents who committed horrendous evils. Plantinga does not rule out that refraining creating certain human beings was not within God’s actualizing power. God could have given human beings free will, and at the same time refrained to create individuals who committed horrendous evils, such as raping children, Hitler, Stalin, professional dehumanizers, and so on. The rest of evils, of course, would be impossible for God to avoid since they are an outcome of free will.
Even we grant Plantinga that it is a logical impossibility for God to give people freedom of will without granting them the capacity to do evil, the problem for a theist is the avoidable evils. It is within God’s power to prevent these contingencies. God’s foreknowledge coupled with his creating power can prevent contingent evils.
 Plantinga has Mackie in mind here who believed that it is impossible for (1) and (2) both to be true. Mackie’s thesis is known as the logical problem of evil. To Mackie, (P) a perfectly good God always would eliminate evils as much as he could and (Q) there is no limit to what an omnipotent God can do. Unlike Plantinga, Mackie believes that (P) and (Q) are both necessary. To Plantinga, a perfectly good God can sometimes permit evil if it is morally justifiable, like in the case of free will, and there is, in fact, a limit to what God could or could not do. Therefore, Plantinga maintains, there is no inconsistency between (1) and (2).
 Plantinga’s view of God is a caring Being that cares about human sufferings. He even suffers when we suffer. In his autobiographical essay, “Self-Profile,” he states, “The chief difference between Christianity and the other theistic religions lies just here: the God of Christianity is willing to enter into and share the sufferings of his creatures, in order to redeem them and his world. Of course this doesn’t answer the question why does God permit evil? But it helps the Christian trust God as a loving father, no matter what ills befall him. Otherwise it would be easy to see God as remote and detached, permitting all these evils, himself untouched, in order to achieve ends that are no doubt exalted but have little to do with us, and little power to assuage our griefs. It would be easy to see him as cold and unfeeling – or if loving, then such that his love for us has little to do with our perception of our own welfare. But God, as Christians see him, is neither remote nor detached. His aims and goals may be beyond our ken and may require our suffering; but he is himself prepared to accept greater suffering in the pursuit of those ends” (36).
 The example of Hitler is not an isolated case or an evidence of particular evil; it is in fact a paradigmatic evil.
 It is also when we assume that free will is a desirable value under all circumstances. Due to the vast amount of evil that occurs in the world, it is doubtful that free will can justify this vastness of evil. As Rowe states, “Someone might hold, for example, that no good is great enough to justify permitting an innocent child to suffer terribly. Again, someone might hold that the mere fact that a given good outweights some suffering and would be lost if the suffering were prevented, is not a morally sufficient reason for permitting the suffering” (“The Problem of Evil and Some Varieties of Atheism 3”).
Hasker, William. “Providence and Evil: Three Theories.” Religious Studies, Vol. 28, No. 1 (Mar., 1992), pp. 91-105. Print.
Plantinga, Alvin. God, Freedom, and Evil. New York: William B. Eerdmans Publishing Company. 2002. Print.
Plantinga, Alvin. “Self-Profile.” In Profiles. Edited by James E. Tomberlin and Peter van Inwagen. Dordrecht: D. Reidel Publishing Company. 1985. Print.
Plantinga, Alvin. The Nature of Necessity. Oxford: Clarendon Press. 1974. Print.
Rowe, William L. “The Problem of Evil and Some Varieties of Atheism.” In The Evidential Argument from Evil. Bloomington: Indiana University Press. 1996. Print.