With respect to the logical problem of evil, Greg Welty argues that Alvin Plantinga’s ‘Free Will defense’ fails. This is because, according to Welty, Plantinga fails to take into account a distinctly Christian belief: Jesus had free will and did not suffer from transworld depravity: it was not possible for Jesus to go wrong with respect to some morally significant action at some time. Since Plantinga’s defense depends on the truth of transworld depravity, and Jesus is a counterexample to it, Plantinga’s defense fails.
Is there a way out for Plantinga? I think there is if it is wrong to assume that Jesus is a member of the set of people that exemplify the property “being created by God.” My thesis is that Jesus does not have a creaturely essence, because if he did, he would not be identical with the Son of God. Surprisingly, then, this core Christian belief exonerates Plantinga from Welty’s charge. To see why, I shall begin by outlining the broad contours of Plantinga’s free will defense; then I shall rehearse Welty’s argument against it; finally, I shall give my rebuttal to Welty’s argument.
Plantinga’s thesis is that the deductive argument for evil fails. The goal of the free will defense (FWD) is to give an account of how the following conjunction (G&E) can be consistent: God is both omnipotent, omniscient and wholly good, and yet evil exists. Wouldn’t a good agent eliminate evil as far as it can? And wouldn’t an omnipotent agent be able to do so, completely? If the answer is ‘yes’ to both of these questions, then the existence of evil is incompatible with the existence of God. But according to Plantinga, there is nothing explicitly or formally contradictory stated in G&E; what is needed is a premise that shows that G&E is implicitly contradictory. One that might do the trick is that God could have made us to act freely and always go right with respect to some morally significant action. Plantinga demurs. God can create free creatures only if God cannot causally determine what they do; and if God cannot causally determine what they do, then he cannot guarantee they will always go right. If he cannot guarantee they will always go right, it is possible that for every morally free person P God could create, if P were created, then P would go wrong with respect to some morally significant action at some time (that is, transworld depravity is possible). The upshot is that it is not within God’s power to create any world that is, in principle, logically possible–only those worlds that are feasible.
Welty directs his attack upon the possibility of transworld depravity. To be sure, he thinks Plantinga’s argument goes through if both  and  are true.
 God is omniscient, omnipotent, and wholly good.
 Every creaturely essence suffers from transworld depravity
But, he says, there is nothing to keep one from revising  to say:
[1*] God is omniscient, omnipotent, and wholly good, and Jesus was a sinless human being.
Since no Christian would want to disagree with [1*], Plantinga’s free will defense is not viable for Christians, because as Welty claims, [1*] is incompatible with . Presumably, Jesus is a member of the class of creaturely essences, and is such that he does not suffer from transworld depravity.
But is he? Is the essence of Jesus a creaturely essence? By “creaturely essence” Plantinga refers to essences that include the property of being created by God (God, Freedom, and Evil, p. 53). The Christian has a good reason for questioning this assumption, because according to Christian belief Jesus is identical with the Son of God, and he is identical with the Son only if every property the Son has is one that Jesus has, and vice versa. One of the properties the Son essentially has is being uncreated. Therefore, Jesus is uncreated, and if he is uncreated, he is not a creaturely essence.
No doubt this is a surprising conclusion, and one we might be skeptical of, but following the work of Tom Morris, it is defensible. In his work The Logic of God Incarnate, Morris distinguishes between the properties that are essential and accidental to human nature, the former being such that a human must have them in order to be human, and the latter are such that they are not essential. Likewise, he distinguishes between properties that are essential and common to human beings. Morris argues that properties like “being created” are common, but not essential to human beings; therefore, human beings need not be created in order to be human. If that were not the case, then Jesus could not be the Son of God. And since it is a core Christian doctrine that Jesus is the Son of God, which is taken to be true by both Welty and Plantinga, it follows that the property of being created by God is not essential to being human. If that is right, then Plantinga’s solution to the logical problem of evil survives survives Welty’s objection.
Update: Greg Welty responds. It’s good too.