This sermon addresses three mental barriers that block God's best for our lives, using the story of the 12 spies from Numbers 13. When Moses sent spies to explore the Promised Land, ten returned with a negative report, saying they felt like grasshoppers compared to the giants living there. This one sentence kept an entire nation from God's best for 40 years. The sermon identifies comparison, feelings, and assumptions as the three mental barriers that prevented the Israelites from entering the Promised Land and that still hinder believers today.