For Catholics, there are different types of Marian prayer that reflect different intentions. Reciting the “Magnificat,” for example, is a way to praise God as Mary did. By reciting the “Angelus,” you commemorate an event in salvation history, one in which Mary had a major role. Such commemorations are also made by the entire Church in the liturgical cycle. At Christmas, for example, the faithful recall Mary’s role in the birth of Christ.
Prayers invoking Mary’s intercession for your own personal intentions are in a separate class, arousing controversy since the time of the Reformation in the sixteenth and seventeenth centuries.
The practice of invoking saintly people for their intercession before God in union with Jesus has roots in sacred Scripture. In this regard, Matthew 18:19-20 refers to saints on earth, and Revelation 18:20 refers to saints in heaven. In the early centuries of the Church, veneration and invocation was offered to those martyred for Christ. The practice derives from the doctrine that the saints are united with Jesus in one mystical body (Rm 12:5).
The practice of calling on Mary for aid also appears to be very old in the Catholic Church. An ancient testimony of confidence in Mary is the prayer Sub Tuum, which historians place in the third century:
We fly to your patronage,
O holy Mother of God;
despise not our petitions in our necessities,
but deliver us always from all dangers,
O glorious and blessed Virgin.
(Dictionary of Mary, p. 143)
This practice became an area of significant disagreement between Catholics and Protestants. After the crisis of the Reformation, the Catholic Council of Trent repeated traditional Christian teaching on the intercession of the saints, which applies preeminently to Mary:
The saints who reign together with Christ, offer up their prayers to God for men; … it is good and useful to invoke them suppliantly and, in order to obtain favors from God through his Son Jesus Christ our Lord who alone is our Redeemer and Saviour, to have recourse to their prayers, assistance and support.
(Theotokos, p. 188)
The Synod of Jerusalem held by the Orthodox Church proclaimed a similar position about a century after Trent. Protestants counter that reliance on Mary and the saints detracts from reliance on Jesus Christ, who is our ‘one mediator’:
For there is one God, and one mediator also between God and men, the man, Christ Jesus, who gave Himself as a ransom for all, the testimony borne at the proper time.
(1 Tm 2:2-5 – New American Bible)
A thorough examination of this topic by the Lutheran-Catholic Dialogue Commission may be found in The One Mediator, The Saints and Mary (Augsburg Press, 1992). An excellent contemporary Catholic reflection on the subject is found in chapter 3 of Pope John Paul II’s 1987 encyclical, Mother of the Redeemer. A small subsection of paragraph 38 of that chapter is as follows:
The Church knows and teaches with Saint Paul that there is only one mediator: “For there is one God, and there is one mediator between God and men, the man Christ Jesus, who gave himself as a ransom for all.” (1 Tm 2:5-6).