I sent this to the members of a Bible study I am in at work when the subject of the Immaculate Conception was brought up:
Mary was preserved exempt from all stain of original sin at the first moment of her animation, and sanctifying grace was given to her before sin could have taken effect in her soul. The formal active essence of original sin was not removed from her soul; it was excluded, it never was in her soul. Simultaneously with the exclusion of sin, the state of original sanctity, innocence, and justice, as opposed to original sin, was conferred upon her, by which gift every stain and fault, all depraved emotions, passions, and debilities, essentially pertaining to original sin, were excluded. But she was not made exempt from the temporal penalties of Adam—from sorrow, bodily infirmities, and death. The immunity from original sin was given to Mary by a singular exemption from a universal law through the same merits of Christ, by which other men are cleansed from sin. Mary needed the redeeming Savior to obtain this exemption, and to be delivered from the universal necessity and debt (debitum) of being subject to original sin. The person of Mary, in consequence of her origin from Adam, should have been subject to sin, but, being the new Eve who was to be the mother of the new Adam, she was, by the eternal counsel of God and by the merits of Christ, withdrawn from the general law of original sin. Her redemption was the very masterpiece of Christ’s redeeming wisdom. He is a greater redeemer who pays the debt that it may not be incurred, than he who pays after it has fallen on the debtor.
I did this just to give “my wayward brothers” a idea of the concept. It is tough being the only “committed” Catholic in the group.