After his prophetic vision of the eternal glories of heaven at the end of the book of Revelation, the apostle John described how he was overwhelmed by what he’d seen.
And when I heard and saw, I fell down to worship at the feet of the angel who showed me these things. But he said to me, “Do not do that. I am a fellow servant of yours and of your brethren the prophets and of those who heed the words of this book. Worship God. (Revelation 22:8-9)
The Roman Catholic Church has committed the same error as John, promoting a mere citizen of heaven to an improper place of authority and honor. Despite the overwhelming testimony of Scripture, the Catholic Church has elevated Mary—a self-described servant of the Lord (Luke 1:38)—to the same level as God, if not higher.
In his Ineffabilis Deus in 1854, Pope Pius IX established as dogma the immaculate conception of Mary, which preserved her from inheriting original sin. His concluding statements provide a good summary of the Catholic view of Mary.
Let all the children of the Catholic Church, who are so very dear to us, hear these words of ours. With a still more ardent zeal for piety, religion and love, let them continue to venerate, invoke and pray to the most Blessed Virgin Mary, Mother of God, conceived without original sin. Let them fly with utter confidence to this most sweet Mother of mercy and grace in all dangers, difficulties, needs, doubts and fears. Under her guidance, under her patronage, under her kindness and protection, nothing is to be feared; nothing is hopeless. Because, while bearing toward us a truly motherly affection and having in her care the work of our salvation, she is solicitous about the whole human race. And since she has been appointed by God to be the Queen of heaven and earth, and is exalted above all the choirs of angels and saints, and even stands at the right hand of her only-begotten Son, Jesus Christ our Lord, she presents our petitions in a most efficacious manner. What she asks, she obtains. Her pleas can never be unheard.  Apostolic Constitution of Pius IX, Ineffabilis Deus: Defining the Dogma of the Immaculate Conception (Boston, MA: St. Paul Books and Media, 1854), 22–23.
Those words are echoed and expanded on throughout Roman Catholic history. Tradition dictates that Mary is part of the monarchy of heaven, soliciting grace and mercy from the Lord on behalf of sinners, and covering sin by distributing from her treasury of merit.  The treasury of merit is a heavenly slush fund Catholics can draw on to reduce their future suffering, or perhaps escape purgatory altogether. The treasury of merit is made up of the excess righteousness achieved by Christ, His mother Mary, and all the saints. Catholics can draw on the treasury of merit through performing rituals or paying indulgences. For further reading refer to Catechism of the Catholic Church, paragraph 1471, 1476–79. She became a co-redeemer with Christ in His suffering on the cross, and is now a co-mediator alongside Him in heaven—essentially an alternative avenue of access to God (a belief that is in utter defiance of 1 Timothy 2:5, where Christ is clearly assigned the exclusive role of mediation between God and man). She replaces the Holy Spirit in bestowing aid and comfort to believers. In effect, she becomes an additional member of the Godhead.
That blasphemy stands in sharp contrast to what Scripture actually says about Mary, and even what she says about herself. Luke 1:46-55 records her humble reaction to the news that she would give birth to the Son of God. Mary said:
My soul exalts the Lord, and my spirit has rejoiced in God my Savior. For He has had regard for the humble state of His bondslave; for behold, from this time on all generations will count me blessed. For the Mighty One has done great things for me; and holy is His name. And His mercy is upon generation after generation toward those who fear Him. He has done mighty deeds with His arm; He has scattered those who were proud in the thoughts of their heart. He has brought down rulers from their thrones, and has exalted those who were humble. He has filled the hungry with good things; and sent away the rich empty-handed. He has given help to Israel His servant, in remembrance of His mercy, as He spoke to our fathers, to Abraham and his descendants forever.
The God she praised—the God of the Bible—does not need to be coaxed or wooed to distribute His blessings. He’s not harsh, distant, or indifferent—He’s gracious, righteous, and merciful. Rather than glorifying herself, she humbly worshiped the Lord.
Scripture actually has very little to say about Mary. There’s no description of her physical appearance, nothing about her life, her later years after Christ’s death, or her own death and burial. And when she does briefly appear with the disciples and the other believers on the day of Pentecost (Acts 1:14), she’s not an object of worship or even a leader in the early church—she’s just one among many. There simply are no biblical examples of anyone ever praying to her, honoring her, or venerating her.
Nor does she play a role in any biblical explanation of the gospel. Paul wrote a magnificent treatise on the doctrine of salvation that we know as the book of Romans, and all he said about the mother of Jesus is that she was “a descendent of David” (Romans 1:3). He’s even less specific in Galatians, another lengthy exposition of the pure, true gospel in which he simply said that Christ was “born of a woman” (Galatians 4:4).
Contrast that with the unending Catholic volumes on the life of Mary, the miracles of Mary, the death of Mary, the apparitions of Mary, and on and on it goes. That’s why it’s often a shock for Catholics to read the Bible and see how little is actually said about Mary.
But that’s what happens when you elevate tradition to the level of Scripture and ascribe to men the infallible characteristics that belong only to God. It warps the truth of Scripture and distorts the person and work of Jesus Christ.
God alone is our Redeemer, our Deliverer, our Benefactor, and our Comforter. He alone is to be worshiped, venerated, adored, and petitioned. The testimony of Scripture is clear.
Gather yourselves and come; draw near together, you fugitives of the nations; they have no knowledge, who carry about their wooden idol and pray to a god who cannot save. Declare and set forth your case; indeed, let them consult together. Who has announced this from of old? Who has long since declared it? Is it not I, the Lord? And there is no other God besides Me, a righteous God and a Savior; there is none except Me. Turn to Me and be saved, all the ends of the earth; for I am God, and there is no other. (Isaiah 45:20-22)