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.

18. When the venerable John could no longer walk to the meetings of the Church but was borne thither by his disciples, he always uttered the same address to the Church; he reminded them of that one commandment which he had received from Christ Himself, as comprising all the rest, and forming the distinction of the new covenant, "My little children, love one another." When the brethren present, wearied of hearing the same thing so often, asked why he always repeated the same thing, he replied, "Because it is the commandment of the Lord, and if this one thing be attained, it is enough" [Jerome].

in word—Greek, "with word … with tongue, but in deed and truth."