This is one of those posts that started out short but ended up being longer the more I thought about it. So, sorry for the length, but here are some thoughts to throw into the mix:
What if one doesn't cooperate in their sanctification? Can you be saved yet unsanctified?
Romans 8:29,30 29For those whom he foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; 30and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified.
Any cooperation by man is the result of the work of saving grace in our life. Yes, we do participate, or cooperate, in our sanctification. But we must be careful to understand that we can take no credit for obeying. The ability to obey God is also a work of grace. God still receives all the glory; just as He does in salvation. In fact, our sanctification is the working out of our salvation (Phil. 2).
Sounds like the Roman Catholic view of justification/sanctification. Why are they wrong, but we are not?
If I'm not mistaken, the RC view is that our cooperation with "infused grace" is necessary for justification. They confuse justification with sanctification, making the former a lifelong process (i.e., not a one-time imputation of righteousness, as we believe) that is never certain until the day of judgment, when God either pronounces a person guilty or innocent on the basis of that lifelong cooperation. It has been a long time since I have discussed RC theology with anyone, so I could be hazy on some of this.
Christ paid all the price for all the sins of the believer, and it is his righteousness that is imputed to us at the time of faith. This twofold obedience that Christ performed is perfect. His work of taking away our sins is complete, and his obedience to the law on our behalf is perfect. It is on this basis alone that we are justified by faith. That is why justification
must be monergistic: There is absolutely nothing we can add to it or do to improve upon Christ's work. As such, it requires no work on our part.
There are, however, things that we can, and must, do in sanctification: making use of the means of grace, watching and praying, drawing near to God, mortifying sin, denying ourselves, gathering together with other believers, etc. This lines up perfectly with Phil. 2:12-13 and, in fact, is even demanded by the text, in my opinion:
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling;
for it is God who is at work in you, both to will and to work for His good pleasure.
In v. 12, Paul refers to their obedience and commands them to "work out [their] salvation with fear and trembling." Why would he refer to their past obedience as well as command them to work out their salvation if he thought that this was monergistic? Furthermore, the use of the phrase "with fear and trembling" seems to reinforce his focus on the Phiilippians' obedience. If I'm not mistaken, this phrase is adverbial in nature, modifying the preceding phrase, "work out." In other words, it tells how this working out is to be done. Would Paul teach that God should work "with fear and trembling"? Not at all.
The boldfaced part does not say that God does the willing and the working for us. It says that he works
in us "to will and to work." I wonder if that little preposition "in" can tell us more than we suspect. It doesn't say that God works "in our lives," "in our works," or "to carry out our works," but rather simply that he works
in us. Paul's view of this divine working in this passage, then, seems limited to the work that God does within a person spiritually. It is heart-work that Paul seems to have in view here, not deed-work.
Something else to consider is the use of the infinitive in the verbs "to will and to work." If I'm not mistaken, the use of the infinitive can indicate the purpose intended by a previous or antecedent action, as in the sentence, "I am going to the store
to buy groceries." The infinitive "to buy" indicates the reason why the action of going to the store takes place. Similarly, perhaps this can be applied to this passage: "To will and to work" indicates the purpose for which God is at work in the Philippians. If so, then it must refer to the Philippians' work and not God's, since otherwise we would have the nonsensical translation, "God is at work to do his work."
Along the same line, I find it noteworthy that the word "work" appears twice, and in both cases it is the same Greek word, though in different forms. I'm no expert on this, but it seems to me that, in light of Paul's emphasis on both the Philippians' obedience and God's internal activity within them, the existence of two identical verbs would indicate separate actions: one carried out by God and the other carried out by the Philippians. Otherwise, again, it would seem redundant: "God works to work." That makes little sense. It makes perfect sense that the text means, God works so that the Philippians, in turn, would work.
If the above is correct, then there is a clear distinction drawn between God's activity and ours. Therefore, I don't think this text calls for a monergistic interpretation. While it does hold up God's grace and inner working as the primary factor in our sanctification--the "efficient cause," if I'm using the terminology correctly--it does not rule out our own work and actions. This is something that I find very comforting about this passage. My flesh is weak and frail, and I am prone to wander, prone to leave the God I love, as the old hymn rightly says. God's grace and power are always there, though, persevering on my behalf, perfecting the good work he began until the day of Christ Jesus (Phil. 1:6), working in me to keep desiring, to keep willing, to keep working for his good pleasure as I work out--not for--my salvation.
I don't think that a fair reading of Phil. 2:12-13 could yield anything other than a synergistic view of sanctification. Good point about koinonia, too. That is a helpful angle.