Today marks the Feast of the Immaculate Conception, the celebration of Mary being freed from original sin. But where do Catholics get this teaching of the Immaculate Conception? Is it biblical? Absolutely.
Check out this great article by Fr. William Saunders about the Immaculate Conception of the Blessed Virgin Mary: http://catholiceducation.org/articles/religion/re0774.html
“The ‘splendor of an entirely unique holiness’ by which Mary is ‘enriched from the first instant of her conception’ comes wholly from Christ: she is ‘redeemed, in a more exalted fashion, by reason of the merits of her Son’. The Father blessed Mary more than any other created person ‘in Christ with every spiritual blessing in the heavenly places’ and chose her ‘in Christ before the foundation of the world, to be holy and blameless before him in love’.” (CCC 492)