Why do Catholics worship Mary so much?
Roman Catholic views of the Virgin Mary as refuge and advocate of sinners, protector from dangers and powerful intercessor with her Son, Jesus are expressed in prayers, artistic depictions, theology, and popular and devotional writings, as well as in the use of religious articles and images.
Catholics believe that worship is due to God alone. Catholics do, however, venerate Mary. In other words, we honor our Blessed Mother with great reverence and devotion because she is the Mother of God. Mary is the model of perfect love and obedience to Christ.
It simply means we turn to her for prayers, something all Christians do when they ask for prayers from their brothers and sisters. So, when Catholics “pray” to Mary, we're not praying in the same way as we pray to God. We're asking for her intercession, the way we ask our brothers and sisters for prayers.
The good news is that we don't need to pray to Mary or to the saints in order to be heard by God. Jesus made this wonderful promise: “Whatever you ask in my name, this I will do, that the Father may be glorified in the Son” (John 14:3).
The earliest recorded prayer to Mary is the sub tuum praesidium (3rd or 4th century) and the earliest depictions of her are from the Priscilla catacombs in Rome (early 3rd century).
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.
John Calvin
Calvin stated that Mary cannot be the advocate of the faithful, since she needs God's grace as much as any other human being. If the Catholic Church praises her as Queen of Heaven, it is blasphemous and contradicts her own intention, because she is praised and not God.
Catholics do not pray to Mary as if she were God. Prayer to Mary is memory of the great mysteries of our faith (Incarnation, Redemption through Christ in the rosary), praise to God for the wonderful things he has done in and through one of his creatures (Hail Mary) and intercession (second half of the Hail Mary).
The crucifix is a visual reminder of Christ's battle over sin, a battle in which He is the Victor! While Christ's Death is memorialized forever in the image of the crucifix, we believe that our Risen Lord is with us, especially in His Sacramental Presence in the Holy Eucharist reserved in the tabernacle.
Catholics worship the One and Only God, who is the Trinity (Father, Son, and Holy Spirit.) He is ONE God, in three divine Persons, and his name is YHWH or Yahweh. The second Person of this Trinity (the Son) came to earth and took on humanity.