| Geneva Study Bible {2} And hereby we do know that we {e} know him, {e} if we keep his commandments. (2) He returns to the testimony of our union with God, that is, to sanctification, declaring what it is to walk in the light, that is, to keep God's commandments. By this it follows that holiness does not consist in those things which men have devised, neither in a vain profession of the gospel. (d) This must be understood of such a knowledge as has faith with it, and not of a common knowledge. (e) For the tree is known by the fruit. People's New Testament 2:3 And by this we do know that we know him. The evidences that we have a saving knowledge of Christ is loyal obedience to his commandments. Wesley's Notes 2:3 And hereby we know that we truly and savingly know him - As he is the advocate, the righteous, the propitiation. If we keep his commandments - Particularly those of faith and love. Scofield Reference Notes [2] commandments John uses "commandments" (1) in the general sense of the divine will, however revealed, "his word" (1Jno 2:5); and (2) especially of the law of Christ Gal 6:2 2Jn 1:5. See, also, Jn 15:10-12. Jamieson-Fausset-Brown Bible Commentary 3. hereby-Greek, "in this." "It is herein," and herein only, that we know (present tense) that we have knowledge of (perfect tense, once-for-all obtained and continuing knowledge of) Him" (1Jo 2:4, 13, 14). Tokens whereby to discern grace are frequently given in this Epistle. The Gnostics, by the Spirit's prescient forewarning, are refuted, who boasted of knowledge, but set aside obedience. "Know Him," namely, as "the righteous" (1Jo 2:1, 29); our "Advocate and Intercessor." keep-John's favorite word, instead of "do," literally, "watch," "guard," and "keep safe" as a precious thing; observing so as to keep. So Christ Himself. Not faultless conformity, but hearty acceptance of, and willing subjection to, God's whole revealed will, is meant. commandments-injunctions of faith, love, and obedience. John never uses "the law" to express the rule of Christian obedience: he uses it as the Mosaic law. Matthew Henry's Concise Commentary 2:3-11 What knowledge of Christ can that be, which sees not that he is most worthy of our entire obedience? And a disobedient life shows there is neither religion nor honesty in the professor. The love of God is perfected in him that keeps his commandments. God's grace in him attains its true mark, and produces its sovereign effect as far as may be in this world, and this is man's regeneration; though never absolutely perfect here. Yet this observing Christ's commands, has holiness and excellency which, if universal, would make the earth resemble heaven itself. The command to love one another had been in force from the beginning of the world; but it might be called a new command as given to Christians. It was new in them, as their situation was new in respect of its motives, rules, and obligations. And those who walk in hatred and enmity to believers, remain in a dark state. Christian love teaches us to value our brother's soul, and to dread every thing hurtful to his purity and peace. Where spiritual darkness dwells, in mind, the judgment, and the conscience will be darkened, and will mistake the way to heavenly life. These things demand serious self-examination; and earnest prayer, that God would show us what we are, and whither we are going. | 
