What makes something possible? Is there a difference among differing possibilities? Is it possible for a lawyer to have taken a different path in the past and become a doctor instead? Or is it possible for someone to born a girl instead of a boy? Or perhaps is it possible for the world to have a different value of the speed of light? Or, what about whether it is possible for the elect to lose their salvation? As it can be seen, all these are "possibilities" in the sense of what can be conceived in the mind, but they are different types of possibilities. The possibility of a different career path depends on decisions made by the person in the past. The second possibility depends on the genotype of the sperm fertilizing the egg (X instead of Y). The third possibility is a variation of the "possible worlds" or "multiverse" hypothesis (a concept which need not really and physically exist except conceptually) The fourth possibility however does not seem to possible, but it is something that can be conceived in the mind, so is it a real possibility?
For those who believe in Scripture and the doctrine of the Perseverance of the Saints, the reason why the fourth possibility does not seem to be a possibility is due to the biblical teaching that God will certainly preserve those whom He calls and saves. John 6:44 states, "No one can come to me unless the Father who sent me draws him. And I will raise him up on the last day." The God who calls a person to salvation will raise him up on the last day. Therefore, how can it be said that the elect have a possibility that they can lose their salvation?
So let us just look at this one particular example here. Is there any sense in which losing salvation is a possibility? And here we must say that, in any actual sense, there is no possibility of the losing of salvation. But yet, according to nature, the elect have no infallible principle placed into them that will make perseverance certain. The elect are not suddenly changed to become like the holy angels, never thinking of not sinning or running away from God. In other words, while God's promise of perseverance is present, everything else in nature and the world seem to indicate otherwise. Professing believers apostatize from the faith, even those that at one time were fervent for the Lord. Others suffer with great doubt over their faith, while on the other spectrum yet others claim to have infallible assurance of their salvation while living like the Devil. The world, this real world, does not seem to make everything so nicely cut and dry, does it?
So is losing one's salvation a possibility? According to God's word, it is not. Looking with the eyes of faith even at the brokenness of this world, we can also say not, since what we see is seldom the heart of the person who claims faith. But from the perspective of nature and the realities of this world, we can say that losing one's salvation is a possibility in this sense: that if it were not for God's promise and God's Spirit, the elect could really lose their salvation. As Mark 13:22 states concerning the false wonders of the false messiahs, these were done to, "lead astray, if possible, the elect." In other words, the elect losing their salvation is a real possibility were it not for the fact of God's promise and the Spirit preserving the elect. Thus, the elect losing their salvation is a possibility, not a real possibility, but what I would call a "hypothetical possibility."
A real possibility refers to something that might happen if something else were or were not the case. It regards things that are variables that could be otherwise in other possible worlds. A hypothetical possibility however refers to something that is possible provided some other principle were to be suspended. In the case of the perseverance of the saints, the principle to be suspended is the intention of God to fulfill His promise, and this principle is necessary in all possible worlds. Hypothetical possibilities are therefore truly hypothetical, in the sense that there is no possible world where they can be realized. Hypothetical possibilities are however different from logical contradictions, like "square circles" or "God creating a stone so heavy He cannot lift it." Hypothetical possibilities are possibilities as they can be conceived, and can be actualized if the principles holding them back (as it were) were suspended.
Thus, in the discussion concerning reprobation, I made the observation that it is a hypothetical possibility that a creature that is reprobated would not be condemned if he did not sin. This is a hypothetical possibility because it is natural and necessary for any fallen creature to sin. But having this hypothetical possibility is meant to show anyone who is interested that God does not just dump innocents into hell, or that He sends people to hell before they have sinned. In the attack against Suprelapsarianism for example, the charge is made that Suprelapsarianism makes God send people on the path of hell even before they are considered sinners. But this charge ignores the two-step process of reprobation, and the hypothetical possibility of the non-damnation of the reprobate, and therefore does not stick. Yes, Supralapsaranism has God electing and reprobating prior to the decree to permit the Fall, but in the decree, reprobation is made to be fully executed only after the Fall (after fallen men sin). The decrees have built-in "clocks" as it were, to be implemented in execution when the conditions within the decree are fulfilled.
This distinction between actual and hypothetical possibility therefore has great hermeneutical potential. Instead of just thinking of things actual and things possible, we should perhaps think of things actual, things actually possible, and things hypothetical possible. Using such categories would aid us greatly in understand concepts like warning against apostasy as something addressing a possibility for the elect (hypothetical possibility), without making such warnings about questioning the salvation of the elect (Arminianism), or stating that they are simply hot air and worrying over nothing, since the elect can never actually fall away (simplistic reasoning by some Calvinists).