21 Sense in which good works are sometimes spoken of as a reason for divine benefits.
The fact that Scripture shows that the good works of believers are reasons why the Lord benefits them is to be so understood as to allow what we have set forth before to stand unshaken: that the efficient cause of our salvation consists in God the Father's love; the material cause in God the Son's obedience; the instrumental cause in the Spirit's illumination, that is, faith; the final cause, in the glory of God's great generosity. These do not prevent the Lord from embracing works as inferior causes. But how does this come about? Those whom the Lord has destined by his mercy for the inheritance of eternal life he leads into possession of it, according to his ordinary dispensation, by means of good works. What goes before in the order of dispensation he calls the cause of what comes after. In this way he sometimes derives eternal life from works, not intending it to be ascribed to them; but because he justifies those whom he has chosen in order at last to glorify them [Rom. 8:30], he makes the prior grace, which is a step to that which follows, as it were the cause. But whenever the true cause is to be assigned, he does not enjoin us to take refuge in works but keeps us solely to the contemplation of his mercy. What sort of thing is this teaching of the apostle: "The wages of sin is death; the grace of the Lord, eternal life" [Rom. 6:23]? Why does he not contrast righteousness with sin, as he contrasts life with death? Why does he not make righteousness the cause of life, as he does sin that of death? For thus an antithesis would duly have been set up that is somewhat broken by this variation. But the apostle intended by this comparison to express what was true: namely, that death is owing to men's deserts but life rests solely upon God's mercy.
In short, by these expressions sequence more than cause is denoted. For God, by heaping grace upon grace, from the former grace takes the cause for adding those which follow that he may overlook nothing for the enrichment of his servants. And he so extends his liberality as to have us always look to his freely given election, which is the source and beginning. For, although he loves the gifts which he daily confers upon us, seeing that they proceed from that source, still it is our part to hold to that free acceptance, which alone can support our souls; and so to subordinate to the first cause the gifts of the Holy Spirit he then bestows that they may nowise detract from it.
(John Calvin Institutes of the Christian Religion, Book III, Chapter 14, Section 21.)