Though God alone is the Cause of conversion, yet He does not convert men immediately, or by immediate operation, but through definite, ordained means. This truth our Lutheran Confession maintains against all forms of enthusiasm (Calvinism, Anabaptism, etc.). The Formula of Concord declares (Thor. Decl., II, 4):
"Moreover, both the ancient and modern enthusiasts have taught that God converts men and leads them to the saving knowledge of Christ through His Spirit, without any created means and instrument, that is, without the external preaching and hearing of God’s Word.”
In these words the Formula of Concord points out the means by which the Holy Spirit works conversion, or regeneration, in the human heart, namely, by “the external preaching and hearing of God’s Word.” As aforesaid, conversion in its proper sense is nothing else than that a person, terrified by the Law on account of his sins, becomes a believer in Christ, trusting for salvation in the divine promises of the Gospel. The Gospel is therefore the object of converting faith; but it also is the means of conversion.1 Through the same means by which God offers to man the merits of Christ (vis evangelii dativa vel collativa) He also works in man faith in the proffered grace (vis evangelii effectiva vel operativa).
This truth is clearly taught in Holy Scripture, e. g., Rom. 10, 17: “Faith cometh by hearing and hearing by the Word of God”; Jas. 1, 18: “Of His own will begat He us with the Word of Truth”; 1 Thess. 1, 5: “Our Gospel came not unto you in word only, but also in power and in the Holy Ghost and in much assurance”; 2 Thess. 2, 13. 14: “God hath chosen you to salvation through sanctification of the Spirit and belief of the truth, where- unto He called you by our Gospel”; 1 Thess. 2, 13: “Ye received the Word of God, . . . not as the word of men, but as it is in truth, the Word of God, which effectually worketh also in you that believe.”
These passages prove that the Gospel is not a “dead letter,” but a living witness, full of power, John 6, 63, because the Holy Spirit is always active and operative through it to inscribe its divine promises into the human heart. Gal. 3, 1—5; Rom. 1, 16; Is. 65, 11.
Luther writes on this point: “Such is the efficacy of the Word whenever it is seriously contemplated, heard, and used that it is bound never to be without fruit, but always awakens new understanding, pleasure, and devoutness and produces a pure heart and pure thoughts. For these words are not inoperative or dead, but creative, living words.” (Large Catechism, Third Commandment, § 100.) The Gospel is therefore the effective means by which the Holy Spirit works faith, or conversion, in man.
Because the Gospel is connected with Baptism, Acts 2, 38, and the Lord’s Supper, Matt. 26, 26—28, also the Sacraments are effective means (media salutis; Gnadenmittel), through which the Holy Spirit either works faith (Baptism: Titus 3,5) or strengthens faith (Lord’s Supper: 1 Cor. 11, 26), in other words, through which He either converts sinners (infants) or confirms and preserves in faith those who are already converted (baptism of adults; Lord’s Supper).
While the Gospel is the proper means by which the Holy Ghost works faith, or conversion, in man, the divine Law is used by God to prepare the sinner for conversion. Saving faith can never exist in a person who has not previously been convinced of his exceeding sinfulness and his state of wrath and damnation, Ps. 34, 18; 51, 17; Is. 66, 2; Acts 2, 37-41; 16, 27—31.
True repentance therefore comprises both contrition (contritio; terrores conscientiae), which is effected by the Law, and faith (fiducia), which is wrought by the Gospel. Hence, in order that sinners may be converted, the preaching of the Gospel must be preceded or accompanied by that of the Law, Rom. 3, 19. 20. In other words, the proclamation of the Law and the Gospel must always go hand in hand, both in their proper connection and with the proper distinction of their functions and purposes, Luke 24, 47.
The Formula of Concord says (Thor. Decl., V, 24—26): “These two doctrines the Law and the Gospel, we believe, . . . should ever and ever be diligently inculcated in the Church of God, . . . although with the proper distinction of which we have heard, in order that through the preaching of the Law and its threats . . . the hearts of impenitent men may be terrified and brought to a knowledge of their sins and to repentance; but not in such a way that they lose heart and despair in this process, but that. . . they be comforted and strengthened again by the preaching of the holy Gospel concerning Christ, our Lord, namely, that to- those who believe the Gospel, God forgives all their sins through Christ, adopts them as children for His sake, and out of pure grace, without any merit on their part, justifies and saves them.”
Hollaz writes in the same tenor: “Conversion, taken in a special sense conversion proper, is that act of grace by which the Holy Spirit excites in the sinner sincere grief for his sins by the Word of the Law and kindles true faith in Christ by the Word of the Gospel that he may obtain remission of sins and eternal salvation.” Doctr. Theol., p. 466.
The preaching of the Law is supported and furthered also by the crosses and afflictions, Luke 15, 14—18; ; Ps. 119, 71, which come upon men and by the manifold earthly blessings by which God calls sinners to repentance, Rom. 2, 4. For this reason the peculiar dealings of God with men have been called concio legis realis, that is, a preaching of the Law by act. However, neither the manifestation of God’s wrath nor of His goodness may take the place of the preaching of the divine Word; for this alone is the means through which the Holy Ghost operates in man toward his conversion, Mark 16, 15. 16.
To the objection that divine monergism in conversion makes the use of external means unnecessary (Calvinism, enthusiasm) we reply that divine monergism certainly excludes human cooperation, but not the employment of the divinely appointed means.
Of this the Formula of Concord writes (Thor. Decl., II, 46): “This doctrine concerning the inability and wickedness of our natural free will and concerning our conversion and regeneration, namely, that it is a work of God alone and not of our powers, is abused in an unchristian manner both by enthusiasts and Epicureans; ... for they say that, since they are unable from their own natural powers to convert themselves to God, they will always strive with all their might against God or wait until God converts them by force against their will; or since they can do nothing in these spiritual things, but everything is the operation of God the Holy Ghost alone, they will regard, hear, or read neither the Word nor the Sacrament, but wait until God, without means, instils into them His gifts from heaven, so that they can truly feel and perceive in themselves that God has converted them.” Luther: “Deus non dat interna nisi per externa. Spiritum Sanctum non mittit absque Verbo.”
Hos. 2:6-7 and many other Bible verses can be used as proof that God loves us so much that He can use external means in addition to the “Word of God” to lead us back to the faith we once had in God, c.f. Google AI Gemini.
When Christian Scriver writes in "Seelen-Schatz", 2.book, 2.preach, $ 31 "This last reminds me that we still have one more means of conversion to discuss, namely the Cross." then he refers primarily to Hos. 2:6-7. In the continuation ($ 32) he also quoting Is. 26, 16, Ps. 77, 3, Is. 48, 10 and Ps. 119: 67. 71.