A brotherly exhortation to thankfulness for the abiding faithfulness of God.

What this letter is. A short, glad note of 31 January 1733 to Else Otterbeck, whose whole point is gratitude: “I, together with you, thank God for His abiding faithfulness… and for the lights which He imparts to you.” But the thankfulness turns into a bracing reminder of why there is so much to be thankful for. In one long, rushing sentence he sets her rescue against what might have been: “You might already be lying in hell, or, like others, be given over to a hardened mind — but God has, in grace, had a watchful care over you; He has called you; He has chosen you out of the earth, that you should become His friend and His own possession.” And this election is not fragile: God is so much in earnest about it “that He will not let Himself be turned away, even by your deviations.” Grace, for Tersteegen, is not a reward for steadiness but a faithfulness that outlasts our unfaithfulness.

The right response to such love, he says, is a wholehearted, repeated surrender — “let there be given to Him once more, and a thousand times over, an irrevocable Yes.” The letter closes with two simple, practical counsels for keeping that gratitude alive. First, keep God before the mind: “Think much, in your heart, upon God and upon His divine perfections.” Second, let devotion govern everything: “Let the loving and still devotion to God be your bridle and rein in your whole walk” — the image of a horse guided by rein — so that no time is dearer to you “than that wherein you can be alone with God, and keep Him company.” He ends with a phrase that could stand as a motto for the whole correspondence: “Let this be our eternal work!”

A few words and echoes.

• Thankfulness for faithfulness. The keynote — gratitude not for gifts received but for God’s anhaltende Treue, the “abiding faithfulness” that keeps hold of the soul; “the inner lights He imparts” are His quiet guidance.
• Chosen you out of the earth. The language of election and calling (an echo of “I have chosen you,” John 15:16; “whom he called, them he also justified,” Romans 8:30) — Else’s whole spiritual life is God’s initiative, not her achievement.
• He will not be turned away by your deviations. The heart of the letter — divine faithfulness that outlasts human failure; grace is not withdrawn at the first stumble (an echo of “if we believe not, yet he abideth faithful,” 2 Timothy 2:13).
• God’s friend and possession. The dignity conferred on the soul — to be God’s “friend” (John 15:14–15) and His “own possession” (Titus 2:14; 1 Peter 2:9).
• An irrevocable Yes. The fitting response — a whole, repeated self-surrender; the “Yes” said “a thousand times over,” out of “an inwardly-sincere heart.”
• Bridle and rein. The image for devotion’s governing role — the “loving and still devotion to God” steering the whole outward life, as reins steer a horse (cf. Psalm 32:9; James 3:2–3).
• Alone with God. The letter’s closing wish — that solitary communion with God be the soul’s most treasured time; “let this be our eternal work.”