The Knowledge of the Holy opens with Tozer's conviction that what comes into our minds when we think about God is the most important thing about us, and that the church had lost a high view of Him. In brief chapters he treats the incomprehensibility of God, the Trinity, His self-existence, immutability, omniscience, omnipotence, transcendence, holiness, sovereignty, justice, mercy, grace and love, each followed by a prayer rather than an argument.

Tozer writes to produce worship, not to settle debates, which makes this a book for devotional reading rather than reference. It suits believers whose sense of God has grown small or sentimental, and it works well read a chapter a day or in a small group willing to sit with one attribute at a time. Widely regarded as the most accessible entry point into the doctrine of God.