In the Bible knowledge is not merely intellectual apprehension. It includes the emotions and personal relationships. Israel has a knowledge of God denied to other nations (Jer. 10: 25; Isa. 37: 20), and Moses is said even to know God face to face (Deut. 34: 10). Among human beings sexual relations are spoken of as ‘knowing’ each other (Gen. 4: 1; Luke 1: 34, AV, NJB) and Hosea uses this language of intimacy to describe God's feelings for Israel (Hos. 4: 1–2).
In the NT knowledge of God is the knowledge of his work fulfilled in Jesus (1 Cor. 2: 2; Phil. 3: 10). There are indeed certain facts which have to be known (2 Tim. 2: 25) as well as the OT scriptures. The knowledge of God's mighty acts in creation and redemption is more than a theoretical knowledge, for it issues in love (1 Cor. 13: 2) and is a gift of the Spirit (1 Cor. 12: 8).
The later books of the NT are aware of some of the ideas that later issued into the religious movement of Gnosticism (gnosis = ‘knowledge’)—a theology, cult, and ethics which regarded salvation as acquired by an esoterical knowledge, often conveyed by a heavenly revealer. Some scholars believe that the Johannine writings have been penetrated by this type of belief. The writings discovered at Nag Hammadi provide good evidence of the beliefs of Gnosticism.