Why do Catholics believe Mary was without sin?

Hi, I have some non Catholic friends who have recently been asking why we believe that Mary is perfect, and I have given them some arguments, but they’re still looking for more. What is the best argument for why Mary is perfect? Thanks!

These links should give you the answers that you need. If you have any further questions or concerns that are not answered by this, please contact Catholic Answers directly.
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Recommended Reading:**
About Mary…where in the Bible does it say…
Was Mary sinless throughout her entire life?
Do I have to believe Mary was sinless to be a Catholic?
Mary’s Sinless Nature
If Mary was sinless, why did she need a Savior?

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