I John 3:14 “We know that we have passed from death unto life, because we love the brethren. He that loveth not his brother abideth in death.”
The context reveals that “He that loveth” is “He that” puts his “love” into action; his “love” is obvious by the way he shows his “love” to the Brethren. “He that loveth … his brother” doesn’t just say that he loves the Brethren, but he loves “in deed and in truth” (I John 3:18), he puts his “love” into action. John explains it this way, “But whoso hath this world’s good, and seeth his brother have need, and shutteth up his bowels of compassion from him, how dwelleth the love of God in him?” (I John 3:17). That is, “He that” does not come to the aid and comfort of “his brother” in times of need is not showing evidence that “the love of God” “dwelleth” “in him”. Thus, “He that loveth not his brother abideth in death.”; that is, by failing to show love to the Brethren he is showing that he is in a state of “death”; that is, he is “without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world” (Ephesians 2:12) and are “alienated and enemies in” their “mind by wicked works” (Colossians 1:21). The person that is only interested in themselves and never comes to the aid of others is showing evidence that they are not “born again” (John 3:8) Children of God. It is not our duty to pass Eternal Judgment upon them; but, those who do not have “the love of God” dwelling in them are usually up to no good and we should be wary of them! On the other hand, those who do have “the love of God” dwelling in them should put great emphasis upon that “love” and seek ways to put that precious “love” into action.