working out your salvation in Philippians 2:12

Paul's "just as you have always obeyed ..." in Philippians 2:12 hopefully helps us understand what "work out your salvation" means in that same verse.  However, there is so much more that Paul has said to the Philippians in this letter up to this point, that helps as well.  In trying to understand what Paul means by the beginning of 2:12, "So then, my beloved, ..." we have to go back before 2:12.  What is 2:12 the conclusion from?

His first exhortation to them is Philippians 1:27, "conduct yourselves in a manner worthy of the gospel of Christ": conduct worthy of the gospel of Christ is a unique phrase here, although conduct worthy of God and worthy of our calling is also in Paul's vocabulary.  Because of the familiarity of the words "gospel" and "Christ" to us, we forget to listen to them like a First Century Philippian would.  Conduct ourselves in a manner worthy of the good news of Messiah.  Hmm.  Do we often think of conduct as something that is to line up with the recent good news we've been given (cf. 1:6,8,10,11)?

Their suffering is also very noteworthy to Paul, and He will mention the suffering of Christ in 2:8, although not by the word suffering, but by the word "obedient" (2:8).  Similarly, the working out of their salvation is compared specifically with their past obedience, as its initial measure.  Other than perhaps the military, we're not as familiar in our culture with devoted obedience as Paul's culture was.  They obeyed while Paul was with them.  But does it say to Paul?  The immediate context is the obedience of Christ to the Father (2:8), and even the assertion that God highly exalted Christ because of His obedience to the Father.  Only then does Paul say "just as you have always obeyed."

The working out of their salvation is an obedience just like they obeyed while Paul was with them, and the "much more" he exhorts them to, is in working out their salvation in the present ("now ... in my absence,"), and for the reason he states in 2:13.

What is the obedience that they always had?  Obedience is a response word.  If what a person does is only the things that a person initiates himself or herself, what is there of obedience in that?  Paul deliberately refers them back to their time with him, and thus to what he has said about it in the letter so far.  He refers them to a finite interval of time, in which they always obeyed, i.e., they responded to imperatives they were under by complying with them.

Christ humbled Himself in "becoming obedient"  (2:8).  This does not mean a transition from disobedience, to obedience, but refers to actions of Christ that complied with the will of God, "to the point of death, even death on a cross." 

Therefore by directly discussing the working out of our salvation in the context of our obedience, Paul wants us to think of it together with instances of our past obedience, as motivation and standard (or if you prefer the order, as standard, and motivation).  He compares this obedience to what they already successfully had done, and to the obedience of Christ to the point of death.  Therefore our salvation places us under obligation to obey, in working it out, and this working out comes with accomplished examples of obedience, for them to consider, their own, and Christ's.  There is no working out of our salvation that cannot draw from them.