Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling. As ye have always obeyed - Continue to act on the same principles and from the same motives; having the same disposition which was in Christ; laboring so as to promote his glory.
Work out your own salvation - Go on, walking by the same rule, and minding the same thing, till your salvation be completed: till, filled with love to God and man, ye walk unblamably in all his testimonies, having your fruit unto holiness, and your end everlasting life.
With fear and trembling - Considering the difficulty of the work, and the danger of miscarriage. If you do not watch, pray and continually depend on God, your enemies will surprise you, and your light and life will become extinct; and then consider what an awful account you must give to Him whose Spirit ye have grieved, and of whose glory ye have come short.