4. The effecting cause of sanctification.
God works, as faith, so also sanctification with his infinite power,47) but in such a way that the Christian according to the new man is active or cooperates in it (cooperatur). Whereas in the origin of faith or in conversion the man only suffers the effect of God without being active (pure passive :se habet), in sanctification he is active or cooperative (active se habet sive cooperatur). The cooperation in sanctification must be understood correctly. It does not happen in such a way that God's action and the action of the new man are coordinated, "as two horses together pull a cart " (F. C. 604, 66 [Trigl. 907, 66 X]), but in such a way that the action of the new man is completely and always subordinated to God's action, always happens only dependenter a Deo. Still differently expressed. It is the Holy Spirit who sets the new man in activity as his living organ and keeps him in activity. All moments are summarized in the words of the Formula of Concord (604, 65. 66 [Trigl. 907, Sol. Decl., II, 65 f. 🔗]): "As soon as the Holy Spirit, through the Word and the holy sacraments, has begun His work of regeneration and renewal in us, it is certain that we can and should cooperate through the power of the Holy Spirit, even though still in great weakness. This, however, is not out of our natural powers of the flesh, but out of the new powers and gifts that the Holy Spirit has begun in us in conversion, as St. Paul expressly admonishes us. This is not to be understood in any other way than that the converted man does good as much and as long as God governs, guides and leads him with his Holy Spirit, and as soon as God withdraws his gracious hand from him, he could not for a moment remain in God's obedience. But if it were to be understood in this way, that the converted man would go along with the Holy Spirit in the same way as two horses pull a chariot together, this could by no means be admitted without detriment to divine truth.
47) 1 Thess. 5:23. 24: Αυτός ο ϑεός άγιάσαι νμας όλοτελεΐς — πιστός ό καλών νμας, δς και ποιήσει. The Holy Spirit, who dwells in Christians as in His temple (1 Cor. 3:16; 6:19), impels them to the killing of the business of the flesh (Rom. 8:13-14). Christians are God's workmanship (ποίημα, creature) even insofar as they do good works (Eph. 2:10).
16 > Sanctification and good works. [English ed. ~ 15]
The question has been discussed whether in the individual spiritual movements and the individual good works the initiative comes from the new man or from the Holy Spirit. Scripture clearly indicates the latter, also tracing every good thought to the authorship of God, 2 Cor. 3:5: οϋχ δτι Ικανοί έομεν άφ' εαυτών λογίσασϑαί τι ώς εξ εαυτών.48)