This is a theological discussion, not an argument, that I get into every now and then. So I have decided to write (type) down my understand of this.
It was not God who said, “work out your own salvation with fear and trembling”, as many will say, rather it was Paul in his 2nd letter to the Philippians where in Chapter 2:10-14 he wrote, “That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father. 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. For it is God which worketh in you both to will and to do of his good pleasure. Do all things without murmurings and disputings:”
Let us take verse 12 out of context, as many do: “Therefore, my beloved, as you 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;” Many believe this to be that Paul is saying that your salvation is up to you, and that you must work it out. We know that Paul does not mean “work so as to earn your own salvation.” Such a statement would contradict the whole of Paul’s gospel which that our salvation is by the grace of God. This is his theme through his message, “For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:”
So what does he mean by, “Work out your own salvation”? Does not mean is he calls the Philippians to put forth real effort into their Christians lives. This is not to work their salvation in the sense of accomplishing it, or earning it, but to work out their salvation, that is to see it evident in every area of their lives, to activate this salvation God freely gave them, and for them to understand it. It can be liken to what you do when you work out a math problem, the answer is in the problem, you just have to work through it to the end, you did not crate the answer, you just put it in a form you can understand.
As Muller said, “The believer must finish, must carry to conclusion, must apply to its fullest consequences what is already given by God in principle . . . He must work out what God in His grace has worked in.”, and Robertson, “He exhorts as if he were an Arminian in addressing men. He prays as if he were a Calvinist in addressing God and feels no inconsistency in the two attitudes. Paul makes no attempt to reconcile divine sovereignty and human free agency, but boldly proclaims both.”. Now much more in my absence: In context, Paul asks for this Christian work ethic he demonstrated while among them, not a work ethic, and to be promoted all the more because of his absence.
Now to the “With fear and trembling” part, Paul’s idea is not that we should live our Christian lives with a constant sense of fear and terror, but that we should live with a fear of failing to work out our own salvation. Again the ‘work’ is not the price of your salvation, rather it is what brings your understanding to you of your salvation.