In this passage with an unusual play on words, we are told to give our salvation a "workout." The Greek word is katergazomai, an interesting compound word that means to "perform." When we are told that God is working in us, the Greek word is energeô, which is the "energy" to do work.
Paul puts it this way: "Now unto him that is able to do exceeding abundantly above all that we ask or think, according to the power that worketh |energeô| in us" (Ephesians 3:20). This "energizing" is an internal and spiritual resource, demonstrated most poignantly by "the exceeding greatness of his power to us-ward who believe, according to the working |energeô| of his mighty power, Which he wrought in Christ, when he raised him from the dead" (Ephesians 1:19-20). Since the energy to produce comes from the same Creator who saved us by grace, He has every right to expect us to "will and to do of his good pleasure."
Peter taught us that God provided "all things that pertain unto life and godliness" (2 Peter 1:3). The Thessalonican church was told that "the word of God . . . effectually worketh also in you that believe" (1 Thessalonians 2:13). And of course, "all scripture . . . is profitable. . . . That the man of God may be perfect, thoroughly furnished unto all good works" (2 Timothy 3:16-17).
Our objective, having been supernaturally supplied by the One who saved us, is to "walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God; Strengthened with all might, according to his glorious power, unto all patience and longsuffering with joyfulness" (Colossians 1:10-11). HMM III