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; 13 for it is God who works in you both to will and to do for His good pleasure. (Phil 2:12-13 – emphasis added)
The word fear in the above passage of Scripture means with reverence and respect. The reference to trembling can be understood to mean with great humility and the type of weakness that causes us to rely completely and solely upon the Lord and His grace. We should also have a huge desire to never offend God through disobedience, as well as a great awe for God’s majesty and holiness.
Now what could the author have meant by “work out your own salvation”? This is the concept of bringing something to completion or maturity, such as when Paul describes himself as straining or “pressing on” toward the goal of being Christlike. (Phil 3:13-14) It’s our responsibility to cooperate with the Lord by obeying His Word and following His plan for our lives. Part of that plan is for us to submit to our Savior by obeying His Word.
I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service. 2 And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God. (Rom 12:1-2)
Obedience and submission to the God whom we revere and respect is only our “reasonable service” according to the passage shown above.
We work out our salvation, then, by going to the source of our salvation—the Word of God—which is the only instrument available to us to renew our hearts and minds as we reverently seek to walk the path of ever-growing spiritual maturity.