Why, my beloved, as you have always obeyed, not as in my presence only, but now much more in my absence…
I. THE NATURE OF SALVATION. It is something to be worked out, a moral process in man himself. On the one hand it is the overcoming and casting out of evil, and on the other the assimilation and development of good. It is restoration from disease to health. The man who is undergoing salvation is both cured and nourished. This is the result of the joint work of God and man — man being able to do his part because God works, and God's working requiring man's work.
II. Paul's putting of the matter is in perfect agreement with the scientific law THAT GROWTH AND DEVELOPMENT ARE DEPENDENT ON THE DUE INTERACTION BETWEEN THE THING THAT HAS TO GROW AND A FITTING ENVIRONMENT. To this biological law all living things are subject. Take, e.g., a corn of wheat: until it is acted on by a fitting environment it can neither grow nor produce fruit. The grains of wheat found in Egyptian mummies might have been thought dead. Yet no sooner were they sown in appropriate soil than they began to grow, simply because they were duly acted on by a fitting environment. Some of them, while the same in appearance with the rest, were dead; they rotted and disappeared because they were incapable of reacting in response to their environment. The first movement proceeds from the surroundings; then follows the response of the germ. Or take our body. Unless we are blessed with sunshine, breathe pure air, eat nourishing food, etc., we can neither develope, nor retain our health. The same principle holds good in disease. A cure depends on proper action from without by medicine or diet. If there is nothing in them to affect our condition, we go from bad to worse, and if our condition is so bad that the medicine works no responsive action, our case is equally hopeless.
III. WHAT IS THE REAL SIGNIFICANCE OF THIS INTERACTION? Is the organism pushed like a ball set in motion? No. Our environment acts on us by becoming food to us, and light, air, heat, as well as bread and water, are food. And food feeds us by becoming one with us, and energizing in us. "They work in you to will and to do." But the power in the food cannot become ours without our effort. We must at least be able to digest. If we cannot do that the most nutritious food will not save us from death. Here again we may say, "Work physically, for it is food that worketh," etc. The same with medicine. Our phrase is, "Has it begun to work?" But the entire man is subject to this great law, man not only as a physical but as a spiritual being.
IV. GOD IS THE ULTIMATE ENVIRONMENT OF OUR SPIRITUAL NATURE, as light and air and food to our body. Therefore, unless He act upon us it is impossible that we should act, nor can His action have any result unless we respond and cooperate. And He does not merely influence us from without, give us commands or present motives; He enters and His energy becomes ours, in virtue whereof we cart will or do. But we must lay hold of Him and assimilate His energy. God can no more become our spiritual light, life, and strength without receptive action than undigested bread can be the staff of life.
V. THAT WHICH IS TRUE OF THE SPIRITUAL LIFE IN GENERAL IS EMPHATICALLY TRUE OF IT AS ENFEEBLED AND DARKENED BY SIN. Unless God come to our help the weakness and darkness cannot be overcome; but equally hopeless is our case unless we receive His help. If we are so far gone in moral corruption that no function of our spiritual being can come into action, anything that God does will no mere avail us than light and water a plant that has withered. God must interfere, and we must open our nature to His influences. He moves first, but there must be a corresponding movement on our side. What is this but what Paul says in the text.
VI. WE ARE SO CONSTITUTED BY GOD THAT WE CANNOT BE SPIRITUALLY HEALTHY WITHOUT HIM. This always was, is, and will be the case. Man's moral weakness and corruption are rooted in the refusal to let God work in him, in the resolve to be self-sufficient. Man without God is like an organism without nourishment. What a starving man is such is the spiritual man without God. Now suppose you went to relieve such a starving man, and he were to say, "I cannot accept your food till I am stronger," you would exclaim, "How can you expect to be strong without food? Can you feed on yourself?" No less absurd is our behaviour in regard to salvation. God is waiting to do His part. You, also, in secret, want to do yours, but you cannot without Him. VII. THOSE WHO HAVE BEGUN TO WORK OUT THEIR SALVATION FIND THAT THEIR ONLY SALVATION IS IN GOD. It is not merely that He must help you now and then. Continuous trust and fellowship are the only safety.
Parallel VersesKJV: Wherefore, my beloved, as ye 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.