I am going on holiday to a country where I may not be able to find a Catholic Church. Is it legitimate for me to receive Holy Communion in the Orthodox Church?
First of all, to be clear, if you cannot get to a Catholic Church on a Sunday or Holyday of Obligation, your obligation to attend Mass ceases: neither God nor the Church commands the impossible. Moral theologians generally reckon that a journey of more than about an hour would excuse from the obligation to attend Mass.
If you are on holiday and there is no Catholic Church available, your desire to participate in the Holy Eucharist at an Orthodox Church is praiseworthy and I would encourage you to attend the Divine Liturgy because it can help us to understand how the Eucharist is celebrated in a different tradition.
As for receiving Holy Communion, it is true that the Code of Canon Law says that a Catholic, for whom it is impossible to approach a Catholic minister, is permitted to receive Communion from a minister in whose Church the sacrament is valid. (Canon 844.2) However, as the Directory for the Application of Principles and Norms on Ecumenism points out, “Catholics ought to show a sincere respect for the liturgical and sacramental discipline of other Churches” (n.107); the Directory also recognises that the other Churches may have more restrictive disciplines in this matter (n.122) and urges that Catholics should respect this discipline if another Church restricts sacramental communion to its own members to the exclusion of others. (n.124)
In fact, the Orthodox Churches do not allow non-Orthodox to receive Holy Communion, so you should not attempt to do so. Rather, if you attend the Divine Liturgy, lift up your heart in adoration within the beautiful surroundings of the Church, perhaps meditating on the Holy Ikons, savouring the beauty of the chant and following some of the prayers if there is a book that you can use with an English translation. Participating in the worship of the Orthodox is also a good occasion to pray for the healing of the ancient division between our Churches.
[UPDATE] A couple of readers have advised me that some Orthodox Churches do allow Catholics to receive Holy Communion in some circumstances. It would be important to check beforehand whether this applies or not, in order to "show sincere respect etc." as mentioned above.
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