Catholic Answers Senior Apologist Jimmy Akin explains the Catholic teaching about the Eucharist, and whether or not it is a "re-sacrifice" of Jesus Christ.
Jimmy Akin was born in Texas and grew up nominally Protestant. At age 20 he experienced a profound conversion to Christ. Planning on becoming a Protestant pastor or seminary professor, Jimmy started an intensive study of the Bible, but the more he immersed himself in Scripture, the more he found...
"Between heresy and schism there is this difference, that heresy perverts dogma, while schism, by rebellion against the bishop, separates from the Church. Nevertheless there is no schism which does not trump up a heresy to justify its departure from the Church."
~ St. Jerome, (In Ep. ad Tit., iii, 10), remarking on how practically and historically, heresy and schism nearly always go hand in hand.