Dear Resa,
If a Catholic marries outside the Catholic Church the marriage is not considered to be valid. This means that every time one has sexual relations he or she is doing so with someone outside of marriage which is a mortal sin. As a result he or she cannot receive Holy Communion.
However, if a Catholic in such a situation lives as a celibate until the marriage is blessed (convalidated), then he or she may go to Confession and receive Holy Communion.
Nothing is worth living in mortal sin—nothing! It all boils down to how much one appreciates the love expressed on that cross on Good Friday. To live in mortal sin is to laugh at His outstretched arms.
Fr. Vincent Serpa, O.P.
