Fear And Trembling

It is a central concern of my ministry: "Work out your salvation with fear and trembling, for it is God who works in you to will and to act." A common interpretation goes something like this: "You’d better perform as a Christian, or you have reason to fear and tremble." But can this be reconciled with salvation by faith? I have interpreted it like this: "You’d better work out the difference between faith and works and why, and do it with fear and trembling, because the consequences are awesome." Commentator Kenneth Wuest says: "The English translation is good if one uses the words 'work out' as one does when referring to the working out of a problem in mathematics." Too many, who go by the name Christian, have not figured it out.