The Marian dogmas are taught by the Catholic Church, but it is commonly held that some of the Marian doctrines such as her bodily accent to heaven are not biblical. But if Catholics believe revelation has ceased, where does this idea come from?
Revelation comes from two sources: Scripture and Tradition
cf. Fr. Chad Ripperger's The Binding Force of Tradition
Marian dogmas like the Immaculate Conception and the Assumption tend to be found much more in Tradition than in the Scripture, though Pope Pius IX's Ineffabilis Deus gives Scriptural basis for the Immaculate Conception.
Liturgy is part of Tradition. Pope Pius XII's 1 Nov. 1950 Apostolic Constitution defining the dogma of the Assumption of the Blessed Virgin Mother, Munificentissimus Deus, says "that, since ancient times, there have been both in the East and in the West solemn liturgical offices commemorating this privilege." He then mentions the Roman liturgy, Gallican sacramentary, and the Byzantine liturgy of the Dormition and Assumption of the Blessed Virgin Mother.
Pius XII also consulted the world's bishops about the definability of the dogma of the Assumption.
The answer lies in 2 Thessalonians 2:15 "Therefore, brothers, stand firm and hold fast to the traditions that you were taught, either by an oral statement or by a letter of ours." and in Matthew 16:18-19 "And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. 19 I will give you the keys to the kingdom of heaven.* Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven.”
The "deposit of faith" is the entire teaching of the Church of Christ, handed down by the Apostles' direct teaching and the Scriptures. There is a long-standing belief in the Church that Mary was assumed into heaven, though there was some dispute as to whether this was truly an apostolic doctrine. The Church, headed by Peter's successor, has the power to "bind and lose" under the guidance of the Holy Spirit, who will not permit "the gates of the netherworld" to prevail. The Church, guided by the Holy Spirit, has determined that this long-standing tradition is apostolic in origin and that it is therefore to be believed as a part of the deposit of the faith. It is telling that this belief is also shared with us by Orthodox Christians.
Lastly, it is not entirely accurate that Catholics believe revelation has ceased. The deposit of faith is complete, and so there is nothing which Catholics can be compelled to believe which is not in that deposit, even though our understanding of that deposit may develop as the Church ages and grows in wisdom. But, Catholics still widely believe in private revelations, which the Church will often promote as "worthy of belief."
If Catholics believe Revelation from God has ceased, how do they defend the Marian dogmas?
The four Marian dogmas of Divine Motherhood, Immaculate Conception, Perpetual Virginity, and Assumption form the basis of Catholic Mariology. These Catholic doctrines about the Virgin Mary have been developed by reference to Sacred Scripture, or Catholic Hermeneutics and Church Tradition.
The Divine Motherhood of Mary can be found in the Scriptures. Mary is the Mother of Jesus and Jesus had two natures united in his human body.
Mary's motherhood of God (Deipara in Latin) is a dogma of the Catholic Church. The term "Mother of God" appears within the oldest known prayer to Mary, the Sub tuum praesidium, which dates to around 250 AD: "Under thy protection we seek refuge, Holy Mother of God". This was the first specifically Marian doctrine to be formally defined by the church, formally affirmed at the Third Ecumenical Council held at Ephesus in 431. This refuted the objection raised by Patriarch Nestorius of Constantinople.
Scriptural basis for the dogma is found in John 1:14 which states "And the Word became flesh, and dwelt among us" and in Galatians 4:4 which states "God sent forth his Son, born of a woman, born under the law". Luke 1:35 further affirms divine maternity by stating: "The holy Spirit will come upon you. ... Therefore the child to be born will be called holy, the Son of God."
The dogmatic constitution Lumen gentium at the Second Vatican Council affirmed Mary as the Mother of God. "The Virgin Mary, who at the message of the angel received the Word of God in her heart and in her body and gave Life to the world, is acknowledged and honored as being truly the Mother of God and Mother of the Redeemer."
This dogma is inherently related to the Christological dogma of the hypostatic union which relates the divine and human natures of Jesus Christ. The Catechism of the Catholic Church teaches that "Mary is truly 'Mother of God' since she is the mother of the eternal Son of God made man, who is God himself." According to Catholic teaching, sourced in the John 1:1-14, Mary did not create the divine person of Jesus, who existed with the Father from all eternity.
The dogma of Mary’s perpetual virginity is perhaps the one that garners the most debate of these four doctrines.
The expression perpetual virginity, ever-virgin, or simply "Mary the Virgin" refers primarily to the conception and birth of Jesus. From the first formulations of faith, especially in baptismal formulas or professions of faith, the Church professed that Jesus Christ was conceived without human seed by the power of the Holy Spirit only. Here lies the decisive meaning of expressions such as "conceived in the womb of the Virgin Mary," "Mary's virginal conception," or "virgin birth." The early baptismal formula (since the 3rd century) state Mary's virginity without further explaining it, but there is no doubt about its physical meaning. Later statements are more explicit. Mary conceived "without any detriment to her virginity, which remained inviolate even after his birth" (Council of the Lateran, 649).
Although never explicated in detail, the Catholic Church holds as dogma that Mary was and is Virgin before, in and after Christ's birth. It stresses thus the radical novelty of the Incarnation and Mary's no less radical and exclusive dedication to her mission as mother of her Son, Jesus Christ. Vatican II reiterated the teaching about Mary, the Ever-Virgin, by stating that Christ's birth did not diminish Mary's virginal integrity but sanctified it . The Catechism of the Catholic Church ponders the deeper meaning of the virgin bride and perpetual virginity (499-507). It also maintains that Jesus Christ was Mary's only child. The so-called "brothers and sisters" are close relations.
There is another explanation in the early Church that assigns some of the brothers of Jesus as step brothers. According to the Protoevangelium of James, Joseph was a widower with children of his who was chosen by the High Priest to be the guardian of the virgin Mary. He said, “[Joseph] you have been chosen by lot to take into your keeping the virgin of the Lord. But Joseph refused, saying: I have children, and I am an old man, and she is a young girl. … And Joseph [though] afraid, and took her into his keeping. And Joseph said to Mary: Behold, I have received you from the temple of the Lord; and now I preserve you in my house” (No. 9).
While not scriptural, this text was widely known and respected in the ancient Church as another explanation for her perpetual virginity. - Understanding the tradition of Mary’s perpetual virginity
The Immaculate Conception is not explicitly mentioned in Scriptures, but there is some Scriptural support for this doctrine.
Sacred Scripture does not explicitly proclaim the doctrine of Mary's Immaculate Conception (i.e. freedom from original sin from the very start of her life). The Catholic Church reflected on this question for centuries, considering biblical texts which seemed related to the topic, at least implicitly. As a result of this prolonged reflection, Pius IX issued a dogmatic definition in 1854 affirming Mary's Immaculate Conception. This declaration (Ineffabilis Deus) indicates that the teaching has been infallibly revealed by God through the living Tradition of the Church. There are also a number of scriptural passages which may be cited in support of the teaching. The angelic greeting in Lk 1:28 refers to Mary as "highly favored" or "full of grace." Both translations refer to the Greek term kecharitomene, the past perfect participle of charis which means a gift, favor or grace. In Biblical Greek, this verbal form suggests permanence and singularity. Such singular, permanent grace in Mary is essentially the same concept affirmed in the dogma of the Immaculate Conception.
Another source of biblical evidence involves the references to Mary as "Woman" (e.g. Jn 2 and Jn 19). The evangelist alludes to Eve, who is called "Woman" in Gen 2. There are other parallels between the Genesis account of Creation and its Fall and the Johannine account of the Redemption. For example, the tree of knowledge caused Adam's death in paradise. The tree of the cross caused the death of Jesus, the new Adam, in Jn 19. So there is a certain biblical parallel between Mary, the Woman of the New Creation, and Eve, the Woman formed in original justice at the first Creation (i.e. before the Fall). This parallel is stated explicitly by very early Church Fathers like Justin Martyr (d ca 160) and Irenaeus (d. ca 220). None of this is explicit proof of the doctrine. However, it is solid support from Scripture alone. - Immaculate Conception: Scripture
The dogma of the Assumption of Mary has also no direct basis in scripture. It was nonetheless declared "divinely revealed," meaning that it is contained implicitly in divine Revelation.
This marian dogma was proclaimed by Pope Pius XII on November 1, 1950 on his Encyclical Munificentissimus Deus.
A distinction needs to be made between Ascension and Assumption. Jesus Christ, Son of God and Risen Lord, ascended into heaven, a sign of divine power. Mary, on the contrary, was elevated or assumed into heaven by the power and grace of God.
The dogma states that "Mary, Immaculate Mother of God ever Virgin, after finishing the course of her life on earth, was taken up in body and soul to heavenly glory." This definition as well as that of the Immaculate Conception makes not only reference to the universal, certain and firm consent of the Magisterium but makes allusion to the concordant belief of the faithful. The Assumption had been a part of the Church's spiritual and doctrinal patrimony for centuries. It had been part of theological reflection but also of the liturgy and was part of the sense of the faithful.
This dogma has no direct basis in scripture. It was nonetheless declared "divinely revealed," meaning that it is contained implicitly in divine Revelation. It may be understood as the logical conclusion of Mary's vocation on earth, and the way she lived her life in union with God and her mission. The assumption may be seen as a consequence of Divine Motherhood. Being through, with, and for her Son on earth, it would seem fitting for Mary to be through, with, and for her Son in heaven, too. She was on earth the generous associate of her Son. The Assumption tells us that this association continues in heaven. Mary is indissolubly linked to her Son on earth and in heaven.
In heaven, Mary's active involvement in salvation history continues: "Taken up to heaven, she did not lay aside her salvific duty... By her maternal love she cares for the brothers and sisters of her Son who still journey on earth" (LG). Mary is the "eschatological icon of the Church" (CCC 972), meaning the Church contemplates in Mary her own end of times.
The definition of the dogma does not say how the transition from Mary's earthly state to her heavenly state happened. Did Mary die? Was she assumed to heaven without prior separation of soul and body? The question remains open for discussion. However, the opinion that Mary passed through death as her Son did, has the stronger support in tradition.
Glorified in body and soul, Mary is already in the state that will be ours after the resurrection of the dead.