“For an all-Orthodox decision to be made, the Synod has to agree.”
Strictly asked as a point of curiousity. If the Synod is required for an “all-orthodox” decision on a matter...can you name the places/dates of such a synod or synods that have explicitly condemned the dogma of papal infallibilty, purgatory, the Immaculate Conception and the filioque.
And if there has been no such all-orthodox synod and decision on one or more of these questions, and as only hypothetical as it might sound, might an Orthodox individual hold to them as a pious opinion in the absence of such an “all-orthodox” decision in a given instance?
There is no need as the Church does not need a synod to reject that which is outside of the Church. As these new concepts are created and added to other faiths, it only serves to increase their distance from the Orthodox Christian faith.
No, all-Orthodox Synods dealt with issues regarding the Church, not things the Church never taught or believed. In other words, if someone began to teach Purgatory in the Orthodox Church, an all-Orthodox Synod would deal with that.
An all-Orthodox Synod was held in Jerusalem in the 17th century to combat a Calvinist mole in the rank of an Ecumenical Patriarch.
And if there has been no such all-orthodox synod and decision on one or more of these questions, and as only hypothetical as it might sound, might an Orthodox individual hold to them as a pious opinion in the absence of such an “all-orthodox” decision in a given instance?
No, unless he could show that this was what the Church believed everywhere and always.