Verse 2. - Another mark by which we can test our love towards the brethren. In verse 1
faith in the Incarnation is shown to involve this love. Here
obedience to God is the test. To obey God proves love to him, and this again involves love of his children.
5:1-5 True love for the people of God, may be distinguished from natural kindness or party attachments, by its being united with the love of God, and obedience to his commands. The same Holy Spirit that taught the love, will have taught obedience also; and that man cannot truly love the children of God, who, by habit, commits sin or neglects known duty. As God's commands are holy, just, and good rules of liberty and happiness, so those who are born of God and love him, do not count them grievous, but lament that they cannot serve him more perfectly. Self-denial is required, but true Christians have a principle which carries them above all hinderances. Though the conflict often is sharp, and the regenerate may be cast down, yet he will rise up and renew his combat with resolution. But all, except believers in Christ, are enslaved in some respect or other, to the customs, opinions, or interests of the world. Faith is the cause of victory, the means, the instrument, the spiritual armour by which we overcome. In and by faith we cleave to Christ, in contempt of, and in opposition to the world. Faith sanctifies the heart, and purifies it from those sensual lusts by which the world obtains sway and dominion over souls. It has the indwelling Spirit of grace, which is greater than he who dwells in the world. The real Christian overcomes the world by faith; he sees, in and by the life and conduct of the Lord Jesus on earth, that this world is to be renounced and overcome. He cannot be satisfied with this world, but looks beyond it, and is still tending, striving, and pressing toward heaven. We must all, after Christ's example, overcome the world, or it will overcome us to our ruin.
By this we know that we are the children God,.... The Ethiopic version reads, "by this know that we love God"; which, in connection with what follows, makes a tautology, and is a proving "idem per idem": whereas the apostle's view is to show when love to the saints is right; and that is,
when we love God, and keep his commandments: love to the brethren may arise from such a cause, as may show that it is not brotherly love, or of a spiritual kind; it may arise from natural relation, or civil friendship, or from a benefit or favour received from them, and from some natural external excellency seen in them; and a man may do acts of love and kindness to the brethren, from what may be called good nature in himself, or with sinister views; but true love to the brethren springs from love to God: such who love the saints aright, and by which they may know they do so, they love them because they themselves love God, and in obedience to his command; they love them because they belong to God, and are the objects of his love; because his grace is wrought in them, and his image stamped upon them.
