The Necessity of Brotherly Love
In this lesson, John continues to illustrate the contrast between "the children of God" and "the children of the devil" (1 John 3:10), presenting two criteria which distinguishes them; practicing righteousness and brotherly love.
It is primarily the subject of "brother love" that John expounds upon throughout the rest of this epistle, including that which serves as our text for this study.
Two compelling reasons are therefore given by John for why we should love one another; It disguishes the children of God and it signifies a passing from death to life.