We know that we have passed from death to life, because we love our brothers. Anyone who does not love remains in death. A real Christian will have an inner yearning to be with other Christians. He will earnestly desire to share in the blessings of the faith with others.
Christian love is self-less.
The one who says 'I love God' yet hates his brother is a liar. For anyone who does not love his brother, whom he has seen, cannot love God, whom he has not seen. This love is referring to sacrificial, substantive love, not romance. If you are Christ's, you should have Christ's attitude toward other people.