66 Placed by the grace of God, as God's Mother, next to her Son, and exalted above all angels and men, Mary intervened in the mysteries of Christ and is justly honored by a special cult in the Church. Clearly from earliest times the Blessed Virgin is honored under the title of Mother of God, under whose protection the faithful took refuge in all their dangers and necessities. Hence after the Synod of Ephesus the cult of the people of God toward Mary wonderfully increased in veneration and love, in invocation and imitation, according to her own prophetic words: "All generations shall call me blessed, because He that is mighty hath done great things to me". This cult, as it always existed, although it is altogether singular, differs essentially from the cult of adoration which is offered to the Incarnate Word, as well to the Father and the Holy Spirit, and it is most favorable to it. The various forms of piety toward the Mother of God, which the Church within the limits of sound and orthodox doctrine, according to the conditions of time and place, and the nature and ingenuity of the faithful has approved, bring it about that while the Mother is honored, the Son, through whom all things have their being and in whom it has pleased the Father that all fullness should dwell, is rightly known, loved and glorified and that all His commands are observed.
Source: Lumen Gentium (Vatican.va)