Andrew Murray emphasizes that only God can truly judge and deal with our sins, warning that many believers fail because they attempt to manage their sin on their own. He urges Christians to surrender their sins to God, allowing Him to execute His judgment and cleanse them from all unrighteousness. Murray highlights the importance of recognizing the various forms of sin, including lust, pride, and idolatry, and encourages believers to bring these before God for His fierce judgment. By doing so, they can experience true freedom and cleansing from their sins. Ultimately, he reassures that God will fulfill His promise to cleanse His people from all filthiness.