Expositor's Bible Commentary Commentary Hebrews 5:14

"But solid food is for fullgrown men, [even] those who by reason of use have their senses exercised to discern good and evil." — Hebrews 5:14 (ASV)

With “but” the author contrasts infants in v.13. Mature people (GK 5455), who have “trained themselves,” need solid food. The NT makes considerable use of metaphors from athletics, as our writer does here. Mature Christians constantly exercise themselves in spiritual perception, and the result is manifest. They can “distinguish good from evil” and, therefore, the implication runs, will not be in danger of doing the wrong thing to which the readers find themselves attracted. Lacking this perception, Christian service will always be immature and partial.