For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.
Herman Bavinck, Our Reasonable Faith, 479–480:
Good works are not independently and newly brought into being by the believers themselves. They lie completely prepared for them all and for each one of them individually in the decision of God’s counsel; they were fulfilled and were earned for them by Christ who in their stead fulfilled all righteousness and the whole law; and they are worked out in them by the Holy Spirit who takes everything from Christ and distributes it to each and all according to Christ’s will.
So we can say of sanctification in its entirety and of all the good works of the church, that is, of all the believers together and of each one individually, that they do not come into existence first of all through the believers, but that they exist long before in the good pleasure of the Father, in the work of the Son, and in the application of the Holy Spirit. Hence all glorying on man’s part is also ruled out in this matter of sanctification. We must know that God in no way becomes indebted to us, and that He therefore never has to be grateful to us, when we do good works; on the contrary, we are beholden to God for them, and have to be grateful to Him for the good works that we do.