“Arminius used such language consistently in his defense of his theological views. But I wanna make it clear here at CTS that Arminius used this ‘contingency’ language in accordance with Luis de Molina’s theology. If contingency exists, then there is the possibility of falling away and repudiating the faith.”
But what about contemporary Molinism? That is a good question indeed. According to Ken Keathley,
“William Lane Craig...asks that if the believer’s will is so overwhelmed by God’s grace, then why does God give the warnings at all? And if the warnings themselves bring about perseverance, does this mean that the believer is capable of apostasy, even if he does not apostatize? HYPOTHETICALLY, AT LEAST, THE ELECT CAN FALL AWAY, but God, using middle knowledge, HAS CHOSEN TO ACTUALIZE A WORLD IN WHICH SCRIPTURAL WARNINGS WILL OPERATE AS MEANS TO KEEP HIS CHILDREN FROM APOSTASY. THIS IS A NOVEL UNDERSTANDING OF PERSEVERANCE...” (Ken Keathley, “Salvation and Sovereignty,” page 186)
Craig asserts then, that there is a possibility of falling away, but a “certainty” that believers will not do so (in other words, the probability is greater that believers will persevere than fall away). Interestingly enough, Arminius confirms Craig’s view with that of the early church fathers:
“On this very subject, too, the greater part of our own doctors lay down a difference: for they say, ‘THAT IT IS POSSIBLE FOR SUCH PERSONS TO FALL AWAY, if their nature, which is inclined to lapses and defection, and if the temptations of the world and Satan, be the only circumstances taken into consideration: but that they will not FINALLY fall away, BECAUSE GOD WILL BRING BACK TO HIMSELF HIS OWN ELECT BEFORE THE END OF LIFE.’ If any one asserts, ‘THAT IT IS NOT POSSIBLE FOR BELIEVERS, in consideration of their being elect persons, finally to fall away from salvation, BECAUSE GOD HAS DECREED TO SAVE THEM,’ I answer, THE DECREE CONCERNING SAVING DOES NOT TAKE AWAY THE POSSIBILITY OF DAMNING, BUT IT REMOVES DAMNATION ITSELF. For ‘to be actually saved,’ and ‘a possibility of not being saved,’ are two things not contrary to each other, but in perfect agreement” (Arminius, “Works,” 1:741).
In other words, the certainty of perseverance does not take away the possibility of non-perseverance. Some at the time of Arminius were saying, “It is not possible for believers...finally to fall away from salvation.” What these believers were saying, however, was that it was “necessary” for believers to persevere. However, no choice is “necessary,” as if it must happen; a choice can only be “certain.” Only when something is “necessary” are other options are “not possible.”
For example, if it is necessary that I go to bed, then this means that I don’t have any other choice. If it is “certain” that I will go to bed, this still leaves the possibility that I might not go to bed. Necessity implies that something is "imposed" on me (such as attendance and homework in classes), while certainty is more related to one's own volition (I may or may not go to the school dance, etc.).
I fear that contemporary believers have the same approach to the Doctrine of Apostasy. Instead of arguing for “certainty of perseverance” and “possibility of apostasy,” they argue for “necessity of perseverance” and “no possibility of apostasy.” This however, simply leads to the idea (as stated in the Doctrine of Eternal Security) that “God MUST persevere me to the end; God CANNOT allow me to fall away.” And what this does, ultimately, is two things: One, it places “necessity” on God, which takes away from God’s freedom to do as He pleases; two, it eliminates human decision; it forces God to “take back” the libertarian freedom He willingly chose to bestow on His creatures. And, remember the words of Molina?
“otherwise, such a conversion to the faith and such perseverance in confessing it would not be meritorious...since there can be neither merit nor moral goodness in any act UNLESS THERE IS FREEDOM, whether of contrariety or of contradiction, with respect to the opposite” (Molina, “Concordia, Pt. IV,” page 246).
For the person who endures to the end, they always had the possibility of falling away; and to the one who does not endure to the end, he or she always had the possibility of persevering. If Molinists intend to be consistent in their view of contingent, creaturely decisions (or “contingents of creaturely freedom,” CCF), then they must acknowledge the possibility of apostasy. One cannot argue “contingency” in his or her theology, and then turn around with perseverance and argue “necessity.”