‘TRUTHFULNESS is a moral attribute of the Godhead, or more properly is an attribute of love: Ex. 34:6; Ps. 25:10; Is. 65:16; Jn. 14:6, 17; 17:3, 17; I 1:9; II Tim. 2:15.
As long as the Godhead are love, They must be truthful, since there would be nothing to prompt untruthfulness. By untruthfulness a selfish heart attempts to gain something that is not due to it, and to cover up its true character. But God’s perfect benevolence simply desires to manifest itself in its true character and has nothing to cover up or conceal. God the Father is said to be “the God of truth” (Is. 65:16); the Lord Jesus could affirm, “I am the way, and the truth, and the life” (Jn. 14:6); the Holy Spirit is “the Spirit of truth” (Jn. 14:17). Truthfulness in absolute perfection is a must, therefore, as long as impartial love prevails. The Scriptures are called “the word of truth” (II Tim. 2:15) because “men moved by the Holy Spirit spoke from God” (II Pe. 1:21).
SUMMARY: To sum up those moral attributes of the Godhead which are in reality attributes of God’s voluntary character of perfect love (impartial good-will toward all moral beings), we may say that:
Perfect love must treat every moral being in absolute righteousness,
Perfect love will be tempered by lovingkindness and mercy toward all men, when righteousness is not sacrificed thereby,
Perfect love will engage the faculties and endowments of personality to devise and produce manifestations of wisdom,
Perfect love will be 100% truthful in all revelations and expressions of factual knowledge.
Holiness is the proper evaluation of this whole wonderful proceeding, but since all actions proceed from love, holiness more specifically is a true evaluation of the voluntary disposition of love.’
Source: Gordon Olson, The Truth Shall Make You Free, The Truth About The Nature and Character of God, p 36-37 (Illinois, Bible Research Fellowship Inc., 1980)