INTEGRITY. A number of variations of the Heb. root תם, are tr. “integrity” in the Eng. VSS of the OT. The many biforms of the root have caused difficulties in the lexica. The Heb. term means “completeness,” “wholeness,” guileless integrity in the sense of artlessness. It occurs some fifty times in the OT, but is tr. “integrity” in only sixteen cases. A clear discussion of the term is as yet unavailable but a good differentiation is found in Genesis 25:27 in the context of the comparison of the character of Esau with that of Jacob. Esau is said to be “cunning,” Heb. יֹדֵ֥עַ, while in contrast Jacob is said to be “artless” and tām is used, KJV reads “plain,” RSV reads “quiet,” JPS reads “quiet” all of which are incorrect. The term is used esp. in the poetic wisdom lit. (Prov 19:1, et al.; Job 2:3, et al.). It is used frequently to describe godly men as Noah, Abraham, David, and also to describe unspecified persons who act out of innocence or without motive, as the bowman described in 1 Kings 22:34, where his shooting the fatal arrow which struck down Ahab in his disguise is described thus: “And a man drew his bow in his artlessness,” a passage wrongly tr. by all the VSS.
The term “integrity” occurs only once in the NT although the idea is quite frequent. The term “integrity” is used in the RSV of Titus 2:7 for Gr. ἀφθοριά, a hapax legomenon in the passage and apparently of Hel. origin. It means “incorruption” or “soundness” and consists of the alpha privitive plus a root meaning “to be festered,” “to be corrupted.” The KJV incorrectly tr., “uncorruptness”; however, the idea if properly understood of integrity as a quality directly dependent not on human virtue, but on God’s work of justification and sanctification is certainly declared in other Scriptures (Matt 6:1-6, et al.).
International Standard Bible Encyclopedia (1915)
The word "integrity" does not occur in the New Testament, but its equivalents may be seen in "sincerity," "truth," the "pure heart," the "single eye," etc. In the above sense of simplicity of intention it is equivalent to being honest, sincere, genuine, and is fundamental to true character.