That the Yes-word given to Jesus must not be revoked by marriage.

What this letter is. A brief, gem-like letter of counsel to a young woman who has just married — and a small theology of how earthly marriage and the soul's prior "betrothal" to Christ belong together rather than compete. Tersteegen's title states the worry he means to lay to rest: that the "Yes-word" given to Jesus must not be revoked by marriage. A soul awakened to Christ has, in effect, said "yes" to Him as the Bridegroom of the soul; does taking an earthly husband cancel that vow?

His answer turns on a deft adaptation of Jesus' own saying about the coin: "Give to the husband what belongs to him, but to God what is God's." The two claims operate on different planes and do not collide. The change of estate "can in no way be prejudicial to the Lord Jesus… in the right and claim He has upon you," because His claim rests on something marriage cannot touch: "He has bought your soul dear enough" (with His blood, as the salutation says), and "the Yes-word once given to Him is unforgotten with Him, since His faithfulness is not annulled by our unfaithfulness." Christ holds His "full claim"; the soul still "belongs to Him… for ever."

The letter's loveliest stroke resolves the apparent rivalry into a richer gift. Rather than losing the heart she once gave Christ, she is now to bring more: "see to it that you bring Him, instead of one, two hearts — which in Jesus shall be One Heart — offering yourself, together with your bodily bridegroom, to the dearest Soul-Bridegroom." Marriage becomes a joint consecration: husband and wife, one flesh, laid together on the altar of Christ. And so the blessing is threefold — the bride content, Jesus content with her, and the writer (who signs himself not "friend" or "brother" but "your weak yet sincere intercessor") content in his soul as well.

A few words and echoes.

• "Give to the husband what belongs to him, but to God what is God's." Matthew 22:21, "Render therefore unto Caesar the things which are Caesar's; and unto God the things that are God's" — the two loyalties distinguished, not opposed.
• "The Bridegroom of your soul… the dearest Soul-Bridegroom." The ancient image of Christ as Bridegroom: 2 Corinthians 11:2, "I have espoused you to one husband… to Christ"; Matthew 9:15; Matthew 25:1–13 (the wise virgins); Revelation 19:7; 21:2, 9; and behind them Hosea 2:19–20 and the Song of Songs. An earthly wedding does not dissolve this deeper espousal.
• "He has bought your soul dear enough… bought through the blood of Jesus." 1 Corinthians 6:20, "ye are bought with a price"; 1 Peter 1:18–19, "redeemed… with the precious blood of Christ"; Acts 20:28.
• "His faithfulness is not annulled by our unfaithfulness." 2 Timothy 2:13, "if we believe not, yet he abideth faithful: he cannot deny himself" — the vow holds because He holds it.
• "He has graciously called you." 2 Timothy 1:9, "who hath… called us with an holy calling."
• "Untiring discipline and enticement." Tersteegen's recurring pairing (Zucht und Lockung) for how grace works — both the corrective "discipline" and the tender "drawing" of Hosea 11:4, "I drew them… with bands of love."
• "Two hearts, which in Jesus shall be One Heart." A fusion of Mark 10:8 ("they twain shall be one flesh") with Acts 4:32 ("of one heart") — the married pair becoming one not merely in flesh but in a shared devotion to Christ.
• "Offering yourself… up to the dearest Soul-Bridegroom." Romans 12:1, "present your bodies a living sacrifice, holy, acceptable unto God" — marriage as a joint living-sacrifice.