to heal: to restore a sick, injured, or broken person to health and wholeness.
This is the New Testament's oldest and weightiest word for healing. At its core it names one thing: bringing someone out of a broken condition back to soundness. Most often that is a body being cured, and the Gospels and Acts use it again and again for the cures Jesus and the apostles performed: a fever broken, a wound closed, a paralyzed man raised from his mat.
But the same word reaches past the body. Centuries before the New Testament, the Greek Old Testament used it to translate the Hebrew word for healing, which covered not only sick bodies but a whole people restored to God, their sin forgiven and their broken relationship mended. The New Testament writers inherited that fuller range. When they quote Isaiah's line, "and I would heal them," or write "by his wounds you were healed," the healing in view is rescue and forgiveness, not a mended body.
What holds these together is a single idea the Bible refuses to split: wholeness. Physical cure and spiritual restoration are two sides of one coin, both pictures of the soundness God gives. That is why this word stands so close to the word for "save." A healed body in the Gospels is regularly a sign of a deeper rescue, and a people healed in the prophets means a people brought home to God.
Nuances
Disputed
Whether this verb is meaningfully distinct from the other main Greek healing word, therapeuo, or whether the two overlap.
- majorityThe two overlap heavily and are often interchangeable. Any difference is a mild tendency (this verb leans toward a completed, decisive cure) rather than a fixed rule; Luke even uses both verbs of the same crowd in one passage.; Louw and Nida, Greek-English Lexicon of the New Testament Based on Semantic Domains, 23.136; Louise Wells, The Greek Language of Healing from Homer to New Testament Times (BZNW 83; de Gruyter, 1998); John Wilkinson, The Bible and Healing (Handsel/Eerdmans, 1998)
- minorityThe two are genuinely distinct: this verb denotes a completed, often divine cure, while therapeuo denotes ongoing service, tending, and treatment.; R. C. Trench, Synonyms of the New Testament, section lxxiv; Albrecht Oepke, "ἰάομαι, ἴασις, ἴαμα, ἰατρός," in Theological Dictionary of the New Testament (TDNT) 3:194-215