Charles Ellicott Commentary Matthew 12:37

"For by thy words thou shalt be justified, and by thy words thou shalt be condemned." — Matthew 12:37 (ASV)

By your words you will be justified — Stripped of the later theological reflections that have gathered around it, the word “justified” means, as its position here shows, the opposite of “condemned.” It signifies being acquitted, either on a specific charge or in a general trial of character.

In this sense, we can understand—without entering the labyrinth of theological debates in which commentators on the Epistles have too often entangled themselves—how people are said to be justified by faith (Romans 3:28 and elsewhere), justified by works (James 2:24), and justified, as in this case, by words.

All three—faith, works, and words—are elements of a person’s character, making or showing what they are. Faith, implying trust and therefore love, justifies as the root element of character. Words justify as its most spontaneous manifestation, and works as its more permanent results.

People can judge words and works to some extent, and they are the tests by which a person should judge themselves. The faith that lies deeper in one's life, however, is known only to God. It is therefore by faith, rather than by works, that a person is justified before God, though this faith is not true faith unless it shapes the character and therefore enables the person to pass the other tests as well.