For this is the declaration, which you have heard from the beginning, that you should love one another.

because this is the message that ye did hear from the beginning, that we may love one another,

For this is the Message you have heard from the beginning - that we are to love one another.

Because this is the word which was given to you from the first, that we are to have love for one another;

For this is the announcement that you heard from the beginning: that you should love one another.

For this is the message we heard from the beginning: we are to love one another.

For this is the message - Margin, "commandment." In the received text, this is ἀγγελία angelia - "a message brought;" in several manuscripts, and in later editions, it is ἐπαγγελία epangelia - "annunciation, announcement;" an order given, or a commandment, Acts 23:21. It is not very material which reading is followed. The word "command" or "rule" would express the sense with sufficient clearness. The reference is to the law given by the Saviour as a permanent direction to his disciples.
That ye heard from the beginning, that we should love one another - See the John 13:34-35 notes; 1-John 2:7 note.

For this is the message - See 1-John 1:5. From the beginning God hath taught men that they should love one another. How essentially necessary this is to the comfort and well-being of man in this state of trial and difficulty, every sensible man must see. All are dependent upon all; all upon each, and each upon all. Mutual love makes this dependence pleasant and doubly profitable. Nothing can be more pleasing to an ingenuous and generous mind than to communicate acts of kindness.

(11) For this is the message that ye heard from the beginning, that we should love one another.
(11) The first reason taken from the authority of God who gives the commandment.

For this is the message,.... Sent from God by Christ, or what he in his ministry declared, and is the commandment which was so frequently urged by him, John 13:34;
that ye have heard from the beginning; of the preaching of the Gospel to them, and of their conversion; see 1-John 2:7;
that we should love one another; to which the command of Christ, the reason with which it is enforced, and the early notice of it, should engage.

We should love the Lord Jesus, value his love, and therefore love all our brethren in Christ. This love is the special fruit of our faith, and a certain sign of our being born again. But none who rightly know the heart of man, can wonder at the contempt and enmity of ungodly people against the children of God. We know that we are passed from death to life: we may know it by the evidences of our faith in Christ, of which love to our brethren is one. It is not zeal for a party in the common religion, or affection for those who are of the same name and sentiments with ourselves. The life of grace in the heart of a regenerate person, is the beginning and first principle of a life of glory, whereof they must be destitute who hate their brother in their hearts.

the message--"announcement," as of something good; not a mere command, as the law. The Gospel message of Him who loved us, announced by His servants, is, that we love the brethren; not here all mankind, but those who are our brethren in Christ, children of the same family of God, of whom we have been born anew.

This is the message. God's charge has always been that we should love each other.
Not as Cain, who was of that wicked one. Cain, who hated and slew his brother, is an extreme type of children of the devil. This hater and murderer is condemned far more severely in the Scriptures than the disobedient Adam.