In Philippians 2:12-13, Paul writes, “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, for it is God who works in you to will and to act according to his purpose.”
This text is often misused to instill fear into people, warning them that it means that they can lose salvation. What does it mean to work out our salvation with fear and trembling? Paul can hardly be encouraging believers to live in a continuous condition of nervousness and anxiety. That would contradict his many other exhortations to peace of mind, courage, and confidence in the God who authors our salvation. The Greek word translated "fear" in this context can equally mean "reverence" or "respect." Paul uses the same phrase in (2 Corinthians 7:15) where he refers to Titus as being encouraged by the Corinthians’ reception of him “with fear and trembling,” that is, with great humility and respect for his position as a minister of the gospel of Jesus Christ. Paul himself came to the Corinthian church in “weakness and fear, and with much trembling” (1 Corinthians 2:3), mindful of the great and awesome nature of the work in which he was engaged.
The sense in which we are to work out our salvation in fear and trembling is twofold. First, the Greek verb rendered “work out” means "to continually work to bring something to completion or fruition." We do this by actively pursuing obedience in the process of sanctification, which Paul explains further in the next chapter of Philippians. He describes himself as “straining” and “pressing on” toward the goal of Christlikeness (Philippians 3:13-14). The “trembling” he experiences is the attitude Christians are to have in pursuing this goal—a healthy fear of offending God through disobedience and an awe and respect for His majesty and holiness. "Trembling" can also refer to a shaking due to weakness, but this is a weakness of higher purpose, one which brings us to a state of dependency on God. Obedience and submission to the God we revere and respect is our “reasonable service” (Romans 12:1-2) and brings great joy. Psalm 2:11 sums it up perfectly: “Serve the LORD with fear and rejoice with trembling.” We work out our salvation by going to the very source of our salvation—the Word of God—wherein we renew our hearts and minds (Romans 12:1-2), coming into His presence with a spirit of reverence and awe.