Answer from: Father Rendy
I would say “no!” Why? First, our liturgical worship, our scripture, our sacraments, our liturgical calendar and the expression of our faith are very similar. Secondly, many families are in a mixed marriage religion relationship – Ukrainian Catholic and Ukrainian Orthodox. There is nothing wrong if they (the family) attend the Orthodox Liturgy and receive Holy Communion, especially on Christmas or Easter or some other special function. Whether the Orthodox priest will give you Holy Communion is another matter. They tend to want to know the person and if he or she went to confession first. On the other hand, we never ask.
I was also told in my studies way back, that if a person (Ukrainian Catholic) wanted to attend the Sunday Liturgy and if there was no Ukrainian Catholic Church, a person should attend a Roman Catholic mass, rather than the Ukrainian Orthodox Liturgy. This was told in a Roman Catholic University. And if there was no Roman Catholic Church, it was alright to attend the Orthodox Church.
In addition, why should our faithful present, pay for some history that happened way back in some dispute over what ever reasons, that divided rather than united.
As long as a person comes up to receive Holy Communion, making an act of contrition first, and with faith in the Body and Blood of Jesus – it is not a sin.
Fr. Rendy Yackimec