Sorry, should read “There is absolutely zero scriptural evidence that Mary is without sin.”
The angel Gabriel said to her, “Hail, full of grace.”
If one is ‘full of grace’ that means that there is no sin within them, for grace is there in its place.
You might want to go back and read Luke 1 again.
Kecharitomene.
Biblically, there is nobody without sin. The only human ever without sin was Jesus himself. That’s why his death on the cross was the most perfect sacrifice for us and we have been redeemed by him.
It’s all very simple really, but like any other cult or belief, you can slap them upside the head with truth all day and it won’t matter. Pray and let the Holy Spirit do his work. The actual amount saved will not be a high number. As a kid I couldn’t get that, now I do however.
The testimony of Scripture about this is clear. Hebrews says that Christ was tempted in all points as we are, yet without sinning (Heb. 4:15). Christ challenged his adversaries to prove that he had sinned and they could not (John 8:46). As the apostle Paul put it, "For our sake he made him [Christ] to be sin, who knew no sin, so that in him we might become the righteousness of God" (2 Cor. 5:21, cf. 1 Pet. 2:22, 1 John 3:5). He is a high priest unlike any other who is "holy, innocent, unstained, separated from sinners, and exalted above the heaven" (Heb. 7:26). His title as the Lamb of God (John 1:29) also draws our attention to his innocence.
Therefore the human nature He received from His handmaid and mother, Mary, had to be sinless.