2:12-18 We must be diligent in the use of all the means which lead to our salvation, persevering therein to the end. With great care, lest, with all our advantages, we should come short. Work out your salvation, for it is God who worketh in you. This encourages us to do our utmost, because our labour shall not be in vain: we must still depend on the grace of God. The working of God's grace in us, is to quicken and engage our endeavours. God's good-will to us, is the cause of his good work in us. Do your duty without murmurings. Do it, and do not find fault with it. Mind your work, and do not quarrel with it. By peaceableness; give no just occasion of offence. The children of God should differ from the sons of men. The more perverse others are, the more careful we should be to keep ourselves blameless and harmless. The doctrine and example of consistent believers will enlighten others, and direct their way to Christ and holiness, even as the light-house warns mariners to avoid rocks, and directs their course into the harbour. Let us try thus to shine. The gospel is the word of life, it makes known to us eternal life through Jesus Christ. Running, denotes earnestness and vigour, continual pressing forward; labouring, denotes constancy, and close application. It is the will of God that believers should be much in rejoicing; and those who are so happy as to have good ministers, have great reason to rejoice with them.

16. Holding forth—to them, and so applying it (the common meaning of the Greek; perhaps here including also the other meaning, "holding fast"). The image of light-bearers or luminaries is carried on from Php 2:15. As the heavenly luminaries' light is closely connected with the life of animals, so ye hold forth the light of Christ's "word" (received from me) which is the "life" of the Gentiles (Joh 1:4; 1Jo 1:1, 5-7). Christ is "the Light of the world" (Joh 8:12); believers are only "light-bearers" reflecting His light.

that I may rejoice in—literally, "with a view to (your being) a subject of rejoicing to me against the day of Christ" (Php 4:1; 2Co 1:14; 1Th 2:19).

that I have not run in vain—that it was not in vain that I labored for your spiritual good.