What Is Faith?

What Is Faith? is a booklet by Dr. R.C. Sproul that examines the biblical meaning of faith, distinguishing it from blind credulity and grounding it in the trustworthiness of God and His Word.

Part of the Crucial Questions series, this booklet draws primarily from Hebrews 11 to offer a clear, accessible account of what Scripture teaches about faith. Sproul begins by distinguishing faith from hope, showing that biblical hope is not uncertain wishfulness but confident expectation rooted in God’s promises. He then explains that faith is not an irrational leap but a reasoned trust in a God who is credible, whose character and track record provide the evidence for things not yet seen.

Across four chapters, Sproul explores key biblical examples of faith—particularly Abraham’s obedience—and addresses the relationship between faith and reason, the nature of saving faith, and the theological significance of Ephesians 2:8, where he argues from the Greek text that faith itself is a gift of God. The booklet concludes by examining the means by which faith is strengthened, including the Word of God, the sacraments, and prayer, emphasizing that believers depend on God’s sanctifying grace for growth in faith throughout the Christian life.

Key Themes

• The biblical distinction between faith and hope as defined in Hebrews 11
• Faith as reasoned trust in God rather than blind credulity
• Saving faith as a gift of God’s grace, not a human achievement
• The role of Scripture, sacraments, and prayer in strengthening faith
• Abraham as a model of radical obedience and trust

Featured Quotes

“When the Bible speaks of hope, it is not referring to a desire for a future outcome that is uncertain, but rather a desire for a future outcome that is absolutely sure.”

“Not only does the beginning of faith depend on the supernatural grace of God, the strengthening of that faith relies on God’s sanctifying grace.”