1 Timothy 2:5-6
For there is one God, and one mediator between God and men, the man Christ Jesus; who gave himself a ransom for all, to be testified in due time.
We have faith in God and in no other, thus we sing:;
Psalm 62:6 He only is my rock and my salvation: he is my defence; I shall not be moved.
And we remind ourselves this:
Psalm 62:5 My soul, wait thou only upon God; for my expectation is from him.
What spirit then, is behind this pen?
Great indeed is Our trust in Mary. The resplendent glory of her merits, far exceeding all the choirs of angels, elevates her to the very steps of the throne of God. Her foot has crushed the head of Satan. Set up between Christ and His Church, Mary, ever lovable and full of grace, always has delivered the Christian people from their greatest calamities and from the snares and assaults of all their enemies, ever rescuing them from ruin.Ubi Primum, February 2, 1849, Pius IX (link to source), section 4
The foundation of all Our confidence, as you know well, Venerable Brethren, is found in the Blessed Virgin Mary. For, God has committed to Mary the treasury of all good things, in order that everyone may know that through her are obtained every hope, every grace, and all salvation. For this is His will, that we obtain everything through Mary.Ubi Primum, February 2, 1849, Pius IX (link to source), section 5
What Scripture will someone try to claim tells us to speak this way about Mary? There are many that teach us to speak this way about God, but none that teach us to make Mary a mediatrix or tell us to have faith in Mary.
I anticipate the usual responses from Rome's advocates for whom an absence of apostolicity is no obstacle. They will first assert that this encyclical is not infallible. Indeed the encyclical does not claim to be infallible: it is paving the way for an allegedly infallible proclamation that was to follow.
Ubi Primum, February 2, 1849, Pius IX (link to source), section 5
Accordingly, We have appointed certain priests of recognized piety and theological learning, as well as several cardinals of the Holy Roman Church who are renowned because of their ability, piety, wisdom, prudence, and knowledge of the things of God; and We have directed them to make, carefully and thoroughly, a most diligent examination into this most important matter and then provide Us with a complete report. Through such a procedure, We feel that We are following in the clearly marked footsteps of Our Predecessors and that We are emulating their example.
The second thing that they may wish to claim is some sort of poetic license for this bishop of Rome. But are we really to take Pius IX's words only poetically? The context of his words is the preparation for inserting the false dogma of the Immaculate Conception into the religion of Rome:
No sooner had We been elevated to the sublime Chair of the Prince of the Apostles and undertook the government of the universal Church (not, indeed, because of Our own worthiness but by the hidden designs of Divine Providence) than We had the great consolation, Venerable Brethren, in recalling that, during the pontificate of Gregory XVI, Our Predecessor of happy memory, there was in the entire Catholic world a most ardent and wondrous revival of the desire that the most holy Mother of God -- the beloved Mother of us all, the immaculate Virgin Mary -- be finally declared by a solemn definition of the Church to have been conceived without the stain of original sin. Both to Our Predecessor and to Us this most devout desire was clearly and unmistakably made manifest by the petitions of illustrious bishops, esteemed canonical chapters, and religious congregations, among whom was the renowned Order of Preachers. These appeals vied with one another in the insistent request that official permission be granted for the word Immaculate to be publicly used and be added to the sacred liturgy, particularly in the Preface of the Mass of the Conception of the Blessed Virgin. With the greatest delight, both Our Predecessor and We acceded to these requests.Ubi Primum, February 2, 1849, Pius IX (link to source), sections 1-2
One thing is wrapped up in another - devotion to Mary is an essential component of Rome's religion, though it was not a part of the apostolic faith. But the faith of Pius IX is the one in which he was raised - which he described this way:
From our earliest years nothing has ever been closer to Our heart than devotion-filial, profound, and wholehearted-to the most blessed Virgin Mary. Always have We endeavored to do everything that would redound to the greater glory of the Blessed Virgin, promote her honor, and encourage devotion to her.Ubi Primum, February 2, 1849, Pius IX (link to source), section 4
Ought not devotion to God to be closer than devotion to any mere creature? Ought not filial, profound, and wholehearted devotion be given to our Father in heaven? How did Jesus teach us to pray - to "Our mother, which art in heaven, hallowed be thy name" or "Our Father"? Which is the prayer that has been prayed continuously for nearly 2000 years? Who on the other hand can produce for us some record of the "Hail Mary" before Nicaea? Who can show us one Western father from the first millennium who said something like "[Mary is] set up between Christ and His Church"?
And even if one could find a "Hail Mary" prayer very early, and some early person who mistakenly used the Marian axe to sever the head (Christ) from the body (His church), what of it? It is not what the apostles taught - it is not the faith once for all delivered to the saints.
It is an innovation whether it was developed in the 19th century with Pius IX, in the middle ages with St. Bernard, or even if it was developed earlier.
The bottom line, dear reader, is this: in whom do you trust? through whom does your salvation come? If it comes through Mary - if you are trusting in her like Pius IX did - you are not properly trusting in Christ, and you will face judgment on that dreadful day of the Lord.