The Fourth Glorious Mystery of the Rosary is the Assumption of the Blessed Virgin Mary, when, at the end of her earthly life, the Mother of God was received, body and soul, into Heaven. The fruit most commonly associated with the mystery of the Assumption is the grace of a happy death. Meditation on the Assumption of the Blessed Virgin Mary:
"And a great sign appeared in heaven: A woman clothed with the sun, and the moon under her feet . . . " (Revelation 12:1). This holy vessel, this Ark of the Covenant, she whom all generations will call blessed because of the great things God has done for her, has completed her life on earth. Mary wants nothing more than to be once again with her Son, and she expects nothing more than to leave this life behind. How could God honor her more than He already has by choosing her to be the Mother of God?
And yet He has one final gift in this life for His most humble of servants. Mary's body shall not suffer the corruption of death, but shall become the first fruits of Christ's Resurrection. Her body, as well as her soul, will be assumed into Heaven and be a symbol for us of the resurrection of the body.
Every Sunday at Mass, we recite those words in the Nicene Creed: "I look forward to the resurrection of the dead and the life of the world to come." And in the Assumption of the Blessed Virgin Mary, we get a glimpse of what they mean. Though we know that, at our death, our body will suffer decay, we can still look forward with hope because we know that Mary's life in the world to come will one day be ours as well, so long as we unite ourselves to her Son.Source: Fourth Glorius Mystery