She was FULL of Grace, Grace is God.... God's spirit, God's will, God's protections, therefore...she was sinless, through God's grace... is how the Catholics view it....in simplistic terms....
Jesus was not yet born, and had not died for our sins yet....but she was still FULL, entirely, of God's grace....there is no sin, when you are FULL of God's grace....because He takes up, every inch of it.
What is GRACE? Mary’s Immaculate Conception made her free from the guilt of Eve by God's grace because of what Jesus would do on the cross.
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