This is the conclusion from the whole. Salvation is not from the will of man, nor from his efforts in striving for it, but is entirely of God’s mercy vouchsafed to whom He pleases. What foundation, then, can be discovered in the word of God for those schemes of self-righteousness, which, in a greater or less degree, make salvation depend on man’s own exertions?
There may be here an allusion to Jacob’s desiring the blessing of the birthright, and his running to provide the venison by which he deceived his father; but his obtaining the blessing was solely the consequence of God’s good pleasure, for the means he employed for the purpose merited punishment rather than success. In like manner, the salvation of any man is not to be ascribed to his own good will and diligent endeavors to arrive at it, but solely to the purpose of God according to election, which is ‘not of works, but of Him that calleth.’ It is true, indeed, that believers both will and run, but this is the effect, not the cause, of the grace of God being vouchsafed to them. ‘Work out your own salvation with fear and trembling.’ To whom is this addressed? To ‘the saints in Christ Jesus,’ in whom God had begun a good work, which He will perform until the day of Jesus Christ — to them who had always obeyed, Philippians 1:1,6,2,2: 12. But besides this, what is the motive or encouragement to work out their salvation? ‘For it is God which worketh in you both to will and to do of His good pleasure.’ Here all the willing and doing of men in the service of God is ascribed to His operation in causing them to will and to do. The whole of the new covenant is a promise of God that He Himself will act efficaciously for the salvation of those whom He will save. ‘I will put my law in their inward parts, and write it in their hearts.’ ‘I will give them one heart, and one way, that they may fear Me for ever.’ ‘I will put My fear in their hearts, that they shall not depart from Me.’ ‘A new heart also will I give you, and a new spirit will I put within you, and I will take away the stony heart out of your flesh, and I will give you a heart of flesh.
And I will put My Spirit within you, and cause you to walk in My statutes, and ye shall keep my judgments and do them,’ Jeremiah 31,32; Ezekiel 36: In this way the means by which God’s elect are brought to Him, their calling, their justification, their sanctification, their perseverance, and their glorification, are all of God, as was shown in the preceding chapter, and not of themselves. ‘There is great folly,’ say Calvin, ‘in the argument that we are possessed of a certain energy in our zeal, but of such a kind as can effect nothing of itself, unless aided by the mercy of Jehovah, since the Apostle shows that we possess nothing of our own, by excluding all our efforts. To infer that we have the power either of running or willing, is a mere cavil, which Paul denies, and plainly asserts that our will or ardor in the race has not the smallest influence in procuring our election. On the other hand, those merit the severest reproof who continue to indulge in sloth, that they may afford room and opportunity for the grace of God to act; since, although their own industry can accomplish nothing, yet the heavenly zeal inspired by the Father of Lights is endued with active efficacy.’
If any shall oppose the declaration of the Apostle, that it is not of him that willeth or of him that runneth, but of God that showeth mercy, and assert that the salvation of man depends on conditions which he is obliged to fulfill, then it may be asked, what is the condition? Is it faith? Faith is the gift of God. Is it repentance? Christ is exalted a Prince and a Savior to give repentance. Is it love? God promises to circumcise the heart in order to love Him. Are they good works? His people are the workmanship of God created unto good works. Is it perseverance to the end? They are kept by the power of God through faith unto salvation. It is true that all these things are commanded and enforced by the most powerful motives, consequently they are duties which require the exercise of our faculties.
But they are assured by the decree of election, and are granted to the elect of God in the proper season; so that, in this view, they are the objects of promise, and the effects of supernatural and Divine influence. ‘Thy people,’ saith Jehovah to the Messiah, ‘shall be willing in the day of Thy power.’ Thus the believer, in running his race, and working out his salvation, is actuated by God, and animated by the consideration of His all-powerful operation in the beginning of his course; of the continuation of His support during its progress; and by the assurance that it shall be effectual in enabling him to overcome all obstacles, and to arrive in safety at its termination.
Robert Haldane commentary on Romans 9 verse 16 (pp. 467-477)