From the Word
13 Do not wonder, brethren, that the world hates you. 14 We know that we have passed out of death into life, because we love the brethren. He who does not love abides in death. 15 Any one who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him. 16 By this we know love, that he laid down his life for us; and we ought to lay down our lives for the brethren.
1 John 3:13–16, RSV
How do we know we have passed from death unto life? Because we love the brethren. When we fully believe in our Saviour’s love, then our hearts respond with perfect love to God and our neighbor. The apostle directed this epistle especially against false Christians; many there are who extol Christ, and fail to bear the fruit of faith. It is not sufficient to boast of having passed from death into life; there must be evidence of the fact. Faith is not an inactive and lifeless thing. When there is faith in the heart, its power will be manifest. Where power is not in evidence, all boasting is false and vain. When the human heart is thrilled with spiritual comfort in its confidence of divine mercy and love, and also warmed into kindness, friendliness, humility, and patience toward the neighbor, envying and despising none, but cheerfully serving all and ministering unto necessity, even to hazarding body and life, then the fruits of faith are manifest.
Such fruits are proof that the believer has truly passed from death into life. Had he not true faith, but doubted God’s grace and love, his heart would not prompt him to manifest love for his neighbor by reason of his love and gratitude to God. This interpretation of God’s Word leaves in its integrity the foundation, justification, or deliverance from death through faith alone. Faith is the first element of Christian doctrine. The next question is whether the faith is real or simulated, being merely a deceptive show and unsupported claim. The clear information imparted by the apostles is that love does not deliver from death, but that deliverance from death and the presence of life become a matter of sight and knowledge in that love has been brought about. With true faith we must have come to the point where we no longer in our pride and conceit despise our neighbor; where we are not filled with envy, hatred, and bitterness; where we desire and promote the interest of our neighbor and do him good to the extent of our power. The reality of the inner life is known by the presence of love, which in turn attests the presence of faith in the heart.
Luther, Martin, and John Sander. Devotional Readings from Luther’s Works for Every Day of the Year. Augustana Book Concern, 1915, pp. 261–62.