John the Apostle
1 John 3:14ESV·traditional attribution

We know that we have passed out of death into life, because we love the brothers. Whoever does not love abides in death.

John Calvin Reformed @genevareformer

14 We know. He commends love to us by a remarkable eulogy, because it is an evidence of a transition from death to life. It hence follows that if we love the brethren we are blessed, but that we are miserable if we hate them. There is no one who does not wish to be freed and delivered from death.

Matthew Henry Presbyterian @wholebiblehenry

The beloved apostle can scarcely touch upon the mention of sacred love, but he must enlarge upon the enforcement of it, as here he does by divers arguments and incentives thereto; as, I. That it is a mark of our evangelical justification, of our transition into a state of life: We know that we have passed from death to life, because we love the brethren, Jo1 3:14.

Commenting on 1 John 3:14-19

John Gill Reformed Baptist @doctorgill

Whosoever hateth his brother is a murderer,.... A soul murderer, as the Ethiopic version renders it; not only of himself, for every sinner, by sinning, wrongs and destroys his own soul; but of his brother whom he hates: he is a murderer of him in his heart, even as he that lusts after a woman hath committed adultery with her in his heart, out of...