Like any prayer, the purpose of the Rosary is to bring us closer to the Lord. Unlike most “vocal prayer”, the Rosary is also meant to be a meditation on the subject matter of the mysteries.
As a vocal prayer, the Rosary serves the usual purposes of such prayer, often described in the mnemonic A.C.T.S. – Adoration of God, Contrition for our sins, Thanksgiving for His Gifts and Supplication for ourselves and others. We can thus offer, and intend, the Rosary for any and all of these intentions. Many Catholics even make a different intention for each decade.
Which leads us to the Rosary as a meditation. All of these same elements can be drawn out of the Rosary by meditating on its mysteries. Contemplating the mysteries we see the reasons to adore and give thanks in the greatness of God and the greatness of His love for us. We see the evil of our sins and the reasons for contrition, and in Jesus and Mary the models of holiness to which we ought to aspire, so that we may share in the joys and glory of eternal life with the Holy Trinity.
Thus, the Rosary leads us to a deepening of Faith, of Hope and of Charity. It is, as many saints have testified, the door of the faithful to a deeper prayer life and a deeper union with God.