David Wilkerson addresses the issue of self-doubt among Christians, emphasizing that feelings of inadequacy stem from a lack of belief in God's promises. He draws parallels to the Israelite spies who, despite witnessing God's power, focused on their weaknesses and declared themselves incapable. Wilkerson asserts that such attitudes are not humble but rather a rejection of God's strength and faithfulness. He challenges believers to trust in God's promises and strength, reminding them that their worth is not defined by their abilities but by their faith in Him. Ultimately, he calls for a shift from self-doubt to belief in God's unwavering support.