I was responding to Father Serge's assertion that someone who is raised as a Catholic can knowingly reject the faith, join the Orthodox Church and be "justified" in doing so. Is that not a mortal sin? Are Catholic doctrines on the papacy and other things meaningless?
What dtstan51 has posted is a bit messy theologically.
Someone whose conscience and heart knew that the Catholic Faith is the fullness of the Gospel would not likely leave the Catholic Church for another Church.
Someone whose conscience and heart knew that the Orthodox Faith is the fullness of the Gospel would not likely leave the Orthodox Church for another Church.
Someone whose conscience and heart leads them from one Church to another cannot be considered as �knowingly reject[ing] the faith�.
If one wishes to be very Latin in theology, for something to be a �mortal sin� the person needs to 1) know the sin they are about to commit is serious, 2) reflect that the sin they are going to commit is serious and 3) commit the sin willingly.
One can certainly argue that it is objectively wrong to leave communion with Rome for Orthodoxy.
One cannot argue that to do so is committing a mortal sin. It is quite possible that the conditions of heart and conscience are such that it is not a sin at all.
And then there are circumstances which form consciences and hearts � people sometimes do get hurt in the Church and their conscience honestly leads them away.
There are many places in official Church documents that explain this clearly.
Yes, Catholic Teaching is important. But if someone who comes to honestly believe that the fullness of the Gospel is found in Orthodoxy and is led by his conscience and heart to become Orthodox one cannot accuse them of committing a mortal sin.
But this is off topic....