Andrew Murray emphasizes the profound significance of the blood of the Lamb in granting believers access to heavenly joy. He explains that the blood not only provides the right to enter heaven but also prepares believers to enjoy its blessings and inspires the eternal song of praise in heaven. The sermon highlights that the redeemed, who have washed their robes in the blood, are eternally grateful for their salvation and the love of Christ that it represents. Murray encourages believers to embrace the cleansing power of the blood, which transforms their lives on earth into a reflection of heavenly joy. Ultimately, he calls for a deeper understanding and appreciation of the blood of Jesus as the foundation of their faith and hope.