Andrew Murray emphasizes the profound promise of Jesus in Mark 11:24, urging believers to fully embrace the faith that assures them they have received what they ask for in prayer. He explains that true faith is not merely a belief in God's word but a deep conviction that God will fulfill His promises, encouraging believers to approach prayer with confidence and trust. Murray warns against limiting God's promises with human reasoning and stresses the importance of believing in the unconditional nature of God's 'all things.' He highlights that prayer is both a means to express our desires and a way to strengthen our faith, ultimately leading to the manifestation of God's blessings in our lives. The sermon concludes with a heartfelt plea for Jesus to teach us how to pray with faith and assurance.