Who’s Doing the Good I Do?

Is it the case that the Christian does not repent but “is repented”?

Is it the case that the Christian does no good works, but that the only good works of the Christian are those of Christ?

This is what the Confessions of the Evangelical Lutheran Church have to say on the matter:

9. Likewise Luther’s statement that man’s will in conversion behaves “altogether passively”5 (that is, that it does nothing at all) must be understood as referring to the action of divine grace in kindling new movements within the will, that is, when the Spirit of God through the Word that has been heard or through the use of the holy sacraments takes hold of man’s will and works the new birth and conversion. But after the Holy Spirit has performed and accomplished this and the will of man has been changed and renewed solely by God’s power and activity, man’s new will becomes an instrument and means of God the Holy Spirit, so that man not only lays hold on grace but also cooperates with the Holy Spirit in the works that follow.
Formula of Concord: Epitome, II

63 But after a man is converted, and thereby enlightened, and his will is renewed, then he wills that which is good, in so far as he is reborn or a new man, and he delights in the law of God according to his inmost self (Rom. 7:22). And immediately he does good, as much and as long as the Holy Spirit motivates him, as St. Paul says, “For all who are led by the Spirit of God are sons of God.”8
64 This impulse of the Holy Spirit is no coercion or compulsion because the converted man spontaneously does that which is good, as David says, “Your people will offer themselves freely on the day you lead your host.”9 Nevertheless, the words of St. Paul apply also to the regenerated, “For I delight in the law of God in my inmost self, but I see in my members another law at war with the law of my mind and making me captive to the law of sin which dwells in my members.” Again, “So then, I of myself serve the law of God with my mind, but with my flesh the law of sin” (Rom. 7:22, 23, 25). And again, “For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh; for these are opposed to each other, to prevent you from doing what you would” (Gal. 5:17).
65 From this it follows that as soon as the Holy Spirit has initiated his work of regeneration and renewal in us through the Word and the holy sacraments, it is certain that we can and must cooperate by the power of the Holy Spirit, even though we still do so in great weakness. Such cooperation does not proceed from our carnal and natural powers, but from the new powers and gifts which the Holy Spirit has begun in us in conversion,
66 as St. Paul expressly and earnestly reminds us, “Working together with him, then, we entreat you not to accept the grace of God in vain.”1 This is to be understood in no other way than that the converted man does good, as much and as long as God rules in him through his Holy Spirit, guides and leads him, but if God should withdraw his gracious hand man could not remain in obedience to God for one moment. But if this were to be understood as though the converted man cooperates alongside the Holy Spirit, the way two horses draw a wagon together, such a view could by no means be conceded without detriment to the divine truth.
67 There is therefore a great difference between baptized people and unbaptized people because, according to the teaching of St. Paul, “all who have been baptized have put on Christ” (Gal. 3:27), are thus truly born again, and now have a liberated will—that is, as Christ says, they have again been made free.2 As a result, they not only hear the Word of God but also are able to assent to it and accept it, even though it be in great weakness.
Formula of Concord: Solid Declaration, II

Theodore G. Tappert, ed., The Book of Concord the Confessions of the Evangelical Lutheran Church. (Philadelphia: Mühlenberg Press, 1959), 472, 533–534.