It’s quite a good question and looks quite serious to me. If it wasn’t serious, let me ask it seriously: “Do Catholics believe that our salvation depends on whether we know if Mary sinned or not, remained a virgin or not, was immaculately conceived or not?”
Let me go a step further: is our salvation based on whether or not Mary ever sinned, remained a virgin or was immaculately conceived?
Code:
In other words, if Mary sinned, didn't remain a virgin or was not immaculately conceived, does that mean we are still dead in our sins?
My understanding of the Catholic Church’s teaching is that we are saved by Grace when we believe in Jesus Christ, the Second Person of the Blessed Trinity made man, and that we shall be judged by our charity (and Faith) showing through our works (or lack thereof).
Does any person’s salvation depend on their belief of the points under discussion? Yes, if that person has promised God that they will accept and believe all that the Catholic Church teaches authoritatively must be believed by Catholics and they know the Church teaches it authoritatively, then the answer is yes, because they are knowingly breaking their promise to God.
If the person has not come to believe that when God revealed in Gen. 3:15 that “He was putting enmity between the Woman and the devil, between Her seed and his”, if they do not understand that this must result in God eternally putting enmity between the Woman and the devil, then they may not be held accountable unless, unless God knows for certain that it is their fault for not coming to believe this because they did not seek the whole truth, with their whole heart, mind, soul, and strength.
St. Paul writing to the Thessalonians, at 2:10, “for those who are perishing because they have not accepted the love of the truth so that they may be saved”, has to be applied to each of us. I am certain most people have failed at some points in their lives to truly love the whole truth with their whole heart, mind, soul and strength. The question then becomes, am I giving God the evidence He needs to see to show true repentance? In Luke 3:8, we find John the Baptist challenging the Pharisees, (and therefore us), "where are your good fruits to show (true) repentance? If we have failed at some points in our lives to love the truth, are we now sincerely loving it and showing God that we only want to believe all that He wants us to believe?
On the question of Mary sinning: If God has one, eternal, infinite, always in the present tense thought, and therefore He is always IN THE PRESENT TENSE SAYING, ‘I am putting enmity between the woman and the devil’, could She sin? If you say “yes”, then how do you explain it without God not being All-Powerful since He is putting enmity between the woman and the devil and this does not keep Her out of the devil’s camp? If you deny that God has one eternal, infinite, always in the present tense thought; then your God does not know all things now; then your God is not the Creator of time because he is subject to it in His thoughts; and His thought could not be infinite because he would think one thing then another; and which “thought” of God is the “Word made Flesh”?
Posts 109, 192, 205 address this issue also. Does anyone deny that in order for God to be truly God, He must have one, infinite, eternal, always in the present tense thought?
Thanks. I’m usually more blunt than that. The point is: If you honor Mary - if you love her like we know Christ does, then she can do great things for your salvation. But knowing her is not necessary for salvation.