Philippians 2:12 (ESV)
12 Therefore, my beloved, as you have always obeyed, so now, not only as in my presence but much more in my absence, work out your own salvation with fear and trembling,
What does Paul mean when he says, "work out your own salvation?"
This is potentially an awkward theological passage, as the verse you have quoted appears to promote the idea that human beings can accomplish their own salvation by their actions. This is a belief called Pelagianism, which has been considered heresy since the earliest days of the Church.
If we look at the Greek, the translation you have quoted is pretty good:
μετα φοβου και τρομου την ἑαυτων σωτηριαν κατεργαζεσθε
With fear and trembling work out your own salvation
ἑαυτων means specifically that the subject of the verb (in this case, Paul's "beloved", the believers in Philippi). The verb is κατεργαζομαι, which does indeed mean "work out", "accomplish for yourself", "bring about".
I think the key thing for interpreting this passage, though, is verse 13:
for it is God who is at work in you, enabling you both to will and to work for his good pleasure. (Philippians 2.13, NRSV)
The "working out" that the Philippians are asked to do, then, is not to use their own innate abilities to accomplish their salvation, but to let God act in and through them. It reflects other Pauline thought, such as "not I, but Christ in me" (from Galatians 2:20).Tweet