The Rosary is a way to enter into the mysteries of Jesus through Mary. The Rosary is a means of drawing closer to Our Lord.
The Joyful Mysteries – which focus on the coming of Christ into this world – make clear that the center of creation is not man, it is not paradise on earth, it is not our brief lives, but Christ Our Lord present among us. The Joyful Mysteries fix our eyes on Him, which helps us to overcome temptations in times of trial.
The Sorrowful Mysteries show us the way we should live on earth, namely to take up our cross daily and follow Christ. It is the great law of love, which consists in forgetting oneself and offering our lives for the glory of God and the salvation of souls. We accomplish this by imitating the sufferings of Our Lord.
The Glorious Mysteries show us the goal for which we live: not an earthly success, but for eternal glory granted by the Resurrection of Our Lord. With these three mysteries, we have all we need for our spiritual lives: the foundation (Emmanuel – God with us), the way (Via Crucis), and the goal (eternal glory). It keeps us free from traveling down a false road towards a wrong end.
The popes often called the Rosary the weapon of Christendom. Pope Pius XI, in his encyclical Ingravescentibus Malis, called the Rosary "a powerful weapon to put the demons to flight, to preserve the integrity of life, to acquire virtue more easily, and in a word to attain real peace among men."
Pope Pius XI continues in this encyclical:
The Holy Rosary, besides, not only serves admirably to overcome the enemies of God and Religion but is also a stimulus and spur to the practice of evangelic virtues which it injects and cultivates in our souls. Above all, it nourishes the Catholic Faith, which flourishes again by due meditation on the sacred mysteries, and raises minds to the truth revealed to us by God.