| Geneva Study Bible {19} And hereby we know that we are of the truth, {20} and shall assure our hearts before him. (19) He commends charity, by three effects: for first of all, by it we know that we are indeed the sons of God, as he showed before. (20) Therefore it comes that we have a quiet conscience, as on the opposite side he that thinks that he has God for a judge, because he is guilty to himself either he is never or else very rarely quiet, for God has a far sharper sight then we, and judges more severely. People's New Testament 3:19 And hereby we know that we are of the truth. Because our love is active and practical. And shall assure our hearts before him. Have a good conscience. Wesley's Notes 3:19 And hereby we know - We have a farther proof by this real, operative love. That we are of the truth - That we have true faith, that we are true children of God. And shall assure our hearts before him - Shall enjoy the assurance of his favour, and the testimony of a good conscience toward God. The heart, in St. John's language, is the conscience. The word conscience is not found in his writings. King James Translators' Notes assure: Gr. persuade Jamieson-Fausset-Brown Bible Commentary 19. hereby-Greek, "herein"; in our loving in deed and in truth (1Jo 3:18). we know-The oldest manuscripts have "we shall know," namely, if we fulfil the command (1Jo 3:18). of the truth-that we are real disciples of, and belonging to, the truth, as it is in Jesus: begotten of God with the word of truth. Having herein the truth radically, we shall be sure not to love merely in word and tongue. (1Jo 3:18). assure-literally, "persuade," namely, so as to cease to condemn us; satisfy the questionings and doubts of our consciences as to whether we be accepted before God or not (compare Mt 28:14; Ac 12:20, "having made Blastus their friend," literally, "persuaded"). The "heart," as the seat of the feelings, is our inward judge; the conscience, as the witness, acts either as our justifying advocate, or our condemning accuser, before God even now. Joh 8:9, has "conscience," but the passage is omitted in most old manuscripts. John nowhere else uses the term "conscience." Peter and Paul alone use it. before him-as in the sight of Him, the omniscient Searcher of hearts. Assurance is designed to be the ordinary experience and privilege of the believer. Matthew Henry's Concise Commentary 3:16-21 Here is the condescension, the miracle, the mystery of Divine love, that God would redeem the church with his own blood. Surely we should love those whom God has loved, and so loved. The Holy Spirit, grieved at selfishness, will leave the selfish heart without comfort, and full of darkness and terror. By what can it be known that a man has a true sense of the love of Christ for perishing sinners, or that the love of God has been planted in his heart by the Holy Spirit, if the love of the world and its good overcomes the feelings of compassion to a perishing brother? Every instance of this selfishness must weaken the evidences of a man's conversion; when habitual and allowed, it must decide against him. If conscience condemn us in known sin, or the neglect of known duty, God does so too. Let conscience therefore be well-informed, be heard, and diligently attended to. | 
