In the 35,000 words of Basic Principles of Biblical Counseling (1975), Crabb gives his view of (1) the shortcomings of five varieties of "secular" counseling, (2) the causes and structure of mental problems, and (3) a Bible-centered approach to counseling.

In Chapter 3, Floating Anchors, Crabb briefly describes the views of Sigmund Freud, "Ego Psychology", Carl Rogers, B.F. Skinner, and "Existentialism" (Victor Frankl) on the causes and structure of mental problems, and he finds each wanting. Each offers valuable insights, but none reflects the Christian view that man is created in the image of God, yet fallen in sin.

In Chapter 4, An Aerial View, Crabb previews his theory: "negative (sinful) feelings" are the result of "negative (sinful) behavior" which is in turn the result of "wrong (sinful) thinking." Repentance is a turn to "right thinking", which necessarily brings "right behavior" and "satisfying feelings" (all p. 47).

In Chapters 5 and 6, Understanding Our Deepest Needs, Crabb identifies our "deepest personal needs" (p. 53) as "significance" (p. 54) and "security" (p. 65).

In Chapter 7, Where Problems Start, Crabb argues that ". . . resentment, guilt and anxiety seem to be the three central underlying disorders in all personal problems and they exist because we think incorrect thoughts" (p. 81).

In Chapter 8, Weaving Tangled Webs, Crabb presents case studies to "see how a counselor, armed with these fundamental ideas, can understand the confusing array of problems confronting him in his office" (p. 84).

In Chapter 9, Hold Your Client Responsible: For What?, Crabb emphasizes the client's need to take personal responsibility for changing his thoughts not just cognitively, but existentially, "dying to the sinful pattern of thinking" (p. 101).

In Chapter 10, The Mood And Goal of Counseling, Crabb argues that secular psychologists cannot give suffering evangelicals the help they need, because "[t]he goal of the biblical counselor is to assist a person to change in the direction of Christlikeness" (p. 110).

Throughout the book, Crabb makes clear that he rejects the concept of mental illness. Mental disorders are the result of a sinful attitude toward God, and can only be healed through confession, remorse, and repentance. He repeatedly discusses the problems of divorce and homosexuality as sinful actions, while emphasizing that any thought or behavior that separates a person from God is a sin. The husband must be head of the household, the wife must submit to him. This submission, however, entails the Christ-like submission that Jesus showed to the Father by coming to Earth in human form. It is not the dominanting submission others often speak about while pointing to the Bible as proof. "[C]hildren are foolish. There are none that seek after God, neither yours nor mine." (p. 86)