You wrote:
“It seems plausible that if a doctrine is important to believe, it would surface SOMEWHERE in scripture.”
Okay, so where is sola scriptura taught in scripture? It isn’t. See how that works?
“And not be CONTRADICTED repeatedly in scripture...”
Mary’s sinlessness is not contradicted ANYWHERE by scripture.
The verses you cited have nothing to do with it.
Indeed, if the traditions of man equal scripture, then why bother having scripture? How does one discern between traditions that are doctrine, and traditions that are merely opinion?
Oh wait - we'll trust the Pope...even 'tho many Popes have led lives that would qualify them as good politicians.
And what does one do when the traditions of man CONTRADICT scripture? For the entire thrust of scripture is that ALL have sinned, and ALL need a Savior.
As Paul rebuked Peter: “14 When I saw that they were not acting in line with the truth of the gospel, I said to Peter in front of them all, “You are a Jew, yet you live like a Gentile and not like a Jew. How is it, then, that you force Gentiles to follow Jewish customs?
15 “We who are Jews by birth and not ‘Gentile sinners’ 16 know that a man is not justified by observing the law, but by faith in Jesus Christ. So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not by observing the law, because by observing the law no one will be justified. 19 For through the law I died to the law so that I might live for God. 20 I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me. 21 I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing!”
If Mary could be without sin, and not need a Savior, then truly Christ died for nothing! If God could skip the sentence of Adam for her, and she could do right things and be justified before God, then Jesus died for no reason.
Look at Romans 3: 9 What shall we conclude then? Are we [Jews] any better? Not at all! We have already made the charge that Jews and Gentiles alike are all under sin. 10 As it is written: “There is no one righteous, not even one; 11 there is no one who understands, no one who seeks God. 12 All have turned away, they have together become worthless; there is no one who does good, not even one.” 13 “Their throats are open graves; their tongues practice deceit.” “The poison of vipers is on their lips.” 14 “Their mouths are full of cursing and bitterness.” 15 “Their feet are swift to shed blood; 16 ruin and misery mark their ways, 17 and the way of peace they do not know.” 18 “There is no fear of God before their eyes.”
19 Now we know that whatever the law says, it says to those who are under the law, so that every mouth may be silenced and the whole world held accountable to God. 20 Therefore no one will be declared righteous in his sight by observing the law; rather, through the law we become conscious of sin.
21 But now a righteousness from God, apart from law, has been made known, to which the Law and the Prophets testify. 22 This righteousness from God comes through faith in Jesus Christ to all who believe. There is no difference, 23 for all have sinned and fall short of the glory of God, 24 and are justified freely by his grace through the redemption that came by Christ Jesus. 25 God presented him as a sacrifice of atonement, through faith in his blood. He did this to demonstrate his justice, because in his forbearance he had left the sins committed beforehand unpunished— 26 he did it to demonstrate his justice at the present time, so as to be just and the one who justifies those who have faith in Jesus.
27 Where, then, is boasting? It is excluded. On what principle? On that of observing the law? No, but on that of faith. 28 For we maintain that a man is justified by faith apart from observing the law. 29 Is God the God of Jews only? Is he not the God of Gentiles too? Yes, of Gentiles too, 30 since there is only one God, who will justify the circumcised by faith and the uncircumcised through that same faith.
I fail to see how it is possible to read that passage as meaning most have sinned, but Mary has not.
I’ve read that when Paul quotes the Old Testament as saying “There is no one righteous, not even one;”, he used the Greek translation, which added the words ‘not even one’ to the translation from the Hebrew. That additional emphasis would seem to rule out interpreting this passage as ‘most have sinned, but Mary has not’.
Indeed, I cannot think of a single passage anywhere that indicates anyone was sinless, except Jesus.
Mary herself knew she needed saving, for in Luke we read, “46 And Mary said: “My soul glorifies the Lord 47 and my spirit rejoices in God my Savior...”
Mary made no claim of being sinless, nor did anyone on her behalf. And when a woman tried to pay attention to Mary, Jesus himself redirected her (“Blessed rather are those who hear the word of God and obey it.”). What use is scripture, if you value the traditions of man above them? Why have a canon, if you ignore the plain teaching found therein?