Harmon speaks on apologetics - the discipline that teaches Christians how to give a reason for their hope.
References: 1 Peter 3:15, Romans 1:16-18, 2 Corinthians 4:4, Colossians 2:10, Colossians 1:9-10, John 20:24-29, John 14:6, 1 Corinthians 15:6, 2 Timothy 3:16, John 1:14, Romans 3:10, Romans 3:23, Hebrews 12:2, Matthew 7:21, John 3:3, 2 Peter 3:18, 2 Timothy 2:23-26, Jude 22