The sin that most grieves God's heart is unbelief. In this classic sermon, David Wilkerson preached about how the book of Hebrews points to the vital importance of faith. God uses the story about unbelief among the Israel nation in the desert wanderings to illustrate how our lack of faith breaks his heart. Modern believers are no better than the Israelites of those ancient days, so we should see the Exodus story as a warning against not taking faith seriously. Our heavenly Father desires our trust in him and his goodness.