Wherefore - Seeing that we have in Christ such a specimen of glory resulting from “obedience†(Phi 2:8) and humiliation, see that ye also be “obedient,†and so “your salvation†shall follow your obedience.
as ye have ... obeyed - “even as ye have been obedient,†namely, to God, as Jesus was “obedient†unto God (see on Phi 2:8).
not as, etc. - “not as if†it were a matter to be done “in my presence only, but now (as things are) much more (with more earnestness) in my absence (because my help is withdrawn from you)†[Alford].
work out - carry out to its full perfection. “Salvation†is “worked in†(Phi 2:13; Eph 1:11) believers by the Spirit, who enables them through faith to be justified once for all; but it needs, as a progressive work, to be “worked out†by obedience, through the help of the same Spirit, unto perfection (2Pe 1:5-8). The sound Christian neither, like the formalist, rests in the means, without looking to the end, and to the Holy Spirit who alone can make the means effectual; nor, like the fanatic, hopes to attain the end without the means.
your own - The emphasis is on this. Now that I am not present to further the work of your salvation, “work out your own salvation†yourselves the more carefully. Do not think this work cannot go on because I am absent; “for (Phi 2:13) it is God that worketh in you,†etc. In this case adopt a rule different from the former (Phi 2:4), but resting on the same principle of “lowliness of mind†(Phi 2:3), namely, “look each on his own things,†instead of “disputings†with others (Phi 2:14).
salvation - which is in “Jesus†(Phi 2:10), as His name (meaning God-Savior) implies.
with fear and trembling - the very feeling enjoined on “servants,†as to what ought to accompany their “obedience†(Eph 6:5). So here: See that, as “servants†to God, after the example of Christ, ye be so “with the fear and trembling†which becomes servants; not slavish fear, but trembling anxiety not to fall short of the goal (1Co 9:26, 1Co 9:27; Heb 4:1, “Let us fear, lest a promise being left us of entering into His rest, any should come short of itâ€), resulting from a sense of our human insufficiency, and from the consciousness that all depends on the power of God, “who worketh both to will and to do†(Rom 11:20). “Paul, though joyous, writes seriously†[J. J. Wolf].