Therefore, my dear friends, as you have always obeyed – not only in my presence, but now much more in my absence – continue to work out your salvation with fear and trembling
NIV
Therefore, my dear ones, as you have always obeyed [my suggestions], so now, not only [with the enthusiasm you would show] in my presence but much more because I am absent, work out (cultivate, carry out to the goal, and fully complete) your own salvation with reverence and awe and trembling (self-distrust, with serious caution, tenderness of conscience, watchfulness against temptation, timidly shrinking from whatever might offend God and discredit the name of Christ).
AMP
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.
KJV
Whatever happens, as citizens of heaven live in a manner worthy of the gospel of Christ. Then, whether I come and see you or only hear about you in my absence, I will know that you stand firm in the one Spirit, striving together with one accord for the faith of the gospel
NIV
Only be sure as citizens so to conduct yourselves [that] your manner of life [will be] worthy of the good news (the Gospel) of Christ, so that whether I [do] come and see you or am absent, I may hear this of you: that you are standing firm in united spirit and purpose, striving side by side and contending with a single mind for the faith of the glad tidings (the Gospel).
AMP
Only let your conversation be as it becometh the gospel of Christ: that whether I come and see you, or else be absent, I may hear of your affairs, that ye stand fast in one spirit, with one mind striving together for the faith of the gospel;
KJV