Very often we hear people says we ought to work out your
salvation with fear and trembling (phil 2:12) to tell christian
that we have to do good works, have to follow this rules/that rules
...etc and all the while ignore the 2 half of the statement in
verse 13.'for it is God who works in you to will and to act
according to his good purpose" saying its God that works in us
giving us both the will(desire) and the ability to do these
things.
farther more, Phil 2 started out with being united in Christ,
having comfort from His love, having fellowship with the Spirit
...etc then comes to doing good works.
Philippians 2:1-18
1If you have any encouragement from being united with Christ, if
any comfort from his love, if any fellowship with the Spirit, if
any tenderness and compassion, 2then make my joy complete by being
like-minded, having the same love, being one in spirit and
purpose.
12Therefore, my dear friends, as you have always obeyednot only in
my presence, but now much more in my absencecontinue to work out
your salvation with fear and trembling, 13for it is God who works
in you to will and to act according to his good purpose.