One way in which the Catholic Church elevates Mary is by claiming that she, much like Jesus, was free from sin both personal and original. This can be fairly easily refuted from Mary's own actions. In Luke 1:47, Mary rejoices in God, her Savior, and in Luke 2:22-24, she offers a sin offering (Leviticus 12:6). If there was anything special about Mary, she did not know it, nor act like she knew it.
The Catholic answer to the former is to claim that yes, God is still Mary's Savior, but He saved her before she "fell into the mud pit", whereas He only saves everyone else after. This is an interesting argument, but it is devoid of all Biblical reasoning. In fact, we can show, Biblically speaking, that it actually doesn't work. Amos 3:7 tells us "Surely the Lord God does nothing, Unless He reveals His secret to His servants the prophets." Did the Lord ever tell a prophet, before Mary's birth or after her death, that He would preserve a woman from original sin for the sole purpose of bearing the Son of God? A simple syllogism for you:
P1: The Lord does nothing without telling a prophet.
P2: God did not tell a prophet He would preserve Mary from sin.
C: The Lord did nothing unusual with regard to Mary.
It's worth noting that we do find Mary in the Old Testament. In fact, the Old Testament foretells the New Testament in painstaking detail, so much so that Jesus rebuked the religious leaders, who of course had studied the scriptures their entire lives, for not recognising Him. Furthermore, after the resurrection, both Jesus (e.g. Luke 24:27) and His Apostles (e.g. Acts 8:35) can be found expounding upon the Old Testament, showing what it says about Jesus. And that, of course, includes things like "...the virgin shall conceive and bear a Son, and shall call His name Immanuel." (Isaiah 7:14). Yet, somehow, none of Catholicism's Marian dogmas can be seen in either the Old or New Testaments. Nothing in the Bible says Mary is free from original sin, nor even hints at it.
The Catholic answer to Mary's sin offering is to say that it's like Jesus' baptism. She didn't need to offer it, she did so to "fulfil all righteousness" (Matthew 3:15). There are two main problems with this. The first is that it is not indicated at all. It reads as it is; it's just a normal Jewish woman fulfilling normal Jewish obligations. Her Son may not have been normal, nor the means by which He was conceived, but there is no indication that there was anything particularly special about her, nor that she, nor anyone, believed there was up until this moment.
In fact, the irony is there is a time in scripture when someone began blessing Mary. In Luke 11:27-28, we read "And it happened, as He spoke these things, that a certain woman from the crowd raised her voice and said to Him, “Blessed is the womb that bore You, and the breasts which nursed You!” But He said, “More than that, blessed are those who hear the word of God and keep it!”"
So of course, Jesus doesn't deny here that Mary is "blessed". And what a great blessing it was! Even speaking as a man, it is an enviable privilege to bear the Son of God in her womb. I'd even trade places with the Penitent Thief just for the chance to speak to Him. Mary got to bring Him into this world, nurse Him at her breasts, hear His first words, teach Him to walk. Yeah, that's quite a blessing. But while not denying the blessing, His response clearly tells us that it doesn't make her particularly special. In truth, a greater blessing is available to all mankind! To "hear the word of God and keep it", which it is worth knowing the Catholic Church desires you not do, bestows upon you a greater blessing than Mary received! Now of course, Mary also received this blessing, but in the identical way to us.
But the second problem with this response is that it defends blasphemy with more blasphemy. You don't get to excuse giving one of Christ's attributes, His sinlessness, to Mary, by attributing another of His attributes, His fulfilment of all righteousness, to her as well. It is a disgraceful insult, both to Christ as God, and to Mary as now being freed from her sin completely (as if even a righteous woman in the flesh could tolerate being worshipped) to endlessly take that which is rightly Christ's alone and apply it to any of His loyal followers.
Biblically speaking, none of this is defensible. Scripture tells us plainly, God alone is good (Matthew 19:17; Mark 10:18; Luke 18:19), we have all gone astray (Isaiah 53:6), and all have sinned and fallen short of the glory of God (Romans 3:23). "But if Jesus is an exception, why can't Mary be?", as one Catholic once asked me. What? You're so committed to replacing Jesus with Mary that literally anything the Bible says about Jesus, you will apply to her? I mean, isn't that the whole point of this whole Mary being sinless thing? It's just one more honor to steal from Christ and bestow upon your pagan goddess version of a woman who would absolutely vomit if she could see what your religion has turned her into? Why can't Mary be an exception? Because she isn't. She is not God with us, she is not the only begotten of the Father, she was not born of a virgin, all authority in Heaven and Earth has not been given to her, the law was not our guardian until she came, her name is not the only name given by which we are to be saved. That all belongs to Jesus. Just because Jesus is an exception doesn't mean Mary is too; Jesus is the exception.
But how could He be if Mary was a sinner? How can I believe the Son of God was born of a woman stained by original sin? The same way I can believe He is descended from the original sinner! He is the seed of Eve! Was Mary born of a virgin? No, even Catholic tradition says her father's name is Joachim. And of course, she descends from Adam and Eve. There was nothing unusual about her conception, her birth, even her very life up until the very night she was visited by the angel. Incredulity that the sinless Christ could be born from a woman as sinful as any other does not change the fact that scripture very clearly tells us that Christ alone knew no sin. The idea that Mary also did not is nothing short of idolatry.