before Vatican II would tell you that to actively participate in a Protestant service would be a mortal sin.

Catholicism for Dummies, Page 188: " Just going to a Christian Sunday worship service isn't good enough. In order for Catholics to satisfy and fulfill the Third Commandment, they must attend a valid Catholic Mass. Going to another denomination for a Sunday worship is nice, but Catholics must also also attend Mass the evening before or sometime during the day on Sunday."


The heretics state that going to a Protestant denomination to fulfill your Sunday obligation "is nice" but "isn't good enough" to fulfill your Sunday obligation.

Every moral theology manual before Vatican II would tell you that to actively participate in a Protestant service would be a mortal sin.


Pope Pius IX, Graves ac diuturnae (#4), March 23, 1875, speaking of a non - Catholic sect: "They [ the faithful] should totally shun their religious celebrations, their buildings, and their chairs of pestilence which they have with impunity established to transmit the sacred teachings. They should shun their writings and all contact with them. They should not have any dealings or meetings with usurping priests and apostates from the faith who dare to exercise the duties of an ecclesiastical minister without possessing a legitimate mission or any jurisdiction."