From a reader:
A friend of mine, who runs the R.C.I.A. program in my parish, recently told me that an Orthodox Mass is just as valid as a Catholic Mass. Is this true? (I thought that the fact that the Orthodox Church is in schism would suggest not.)
What you were told is correct in its essence, though we have to tweak a couple things.
First, the Eucharistic liturgy which the Orthodox celebrate is generally called the “Divine Liturgy” rather than Mass. Furthermore, the Eastern Churches in union with Rome also called their “Mass” the “Divine Liturgy”.
Second, the issue of schism would not necessarily invalidate the consecration of the Eucharist. For example, were the SSPX in schism, officially declared as such, their Masses would still be valid. They have valid apostolic succession, valid Holy Orders, valid rites and matter and intention.
Third, you can fulfill your Sunday Mass obligation by attending Masses, Divine Liturgies, of the Eastern Catholic Churches, but not those of Orthodox Churches. The Eastern Catholic Churches are celebrating in a Catholic rite. If you go to a Divine Liturgy of any Eastern Church in union with Rome, you may receive Holy Communion, which will be given under both kinds, Blood and Body together, directly in the mouth with a small spoon (don’t close your mouth on it). You can fulfill your Mass obligation at a chapel of the SSPX as well, for they are using, obviously, a Catholic rite. Their union with Rome is questionable in some respects, but the Holy See does not at this time say they are in schism.
I warmly recommend that you and all the readers at some time try to attend a Sunday Divine Liturgy in some Eastern Catholic Church.