Matthew

“The category of validity allows for ecclesiastical lines to be crossed, even if there is no communion between ecclesial bodies. It allows Rome to recognize “valid” sacraments even outside its own self-understanding of the Church (i.e., the Church is only the Roman Catholic Church): Eastern Christians who are in fact separated in good faith from the Catholic Church, if they ask of their own accord and have the right dispositions, may be admitted to the sacraments of Penance, the Eucharist and the Anointing of the Sick. Further, Catholics may ask for these same sacraments from those non-Catholic ministers whose churches possess valid sacraments, as often as necessity or a genuine spiritual benefit recommends such a course and access to a Catholic priest is physically or morally impossible. (Vatican II, Orientalium Ecclesiarium, 1964) For the Orthodox, communion and all the sacraments exist only within one ecclesiastical communion. That is, Orthodox Christians may only receive the sacraments from Orthodox clergy. Likewise, Orthodox clergy may only give the sacraments to Orthodox Christians. (In cases of emergency, non-Orthodox are welcome to convert in order to receive the sacraments.)”
― Andrew Stephen Damick, Orthodoxy and Heterodoxy: Exploring Belief Systems through the Lens of the Ancient Christian Faith