The Church teaches that salvation is found only within it. Outside of the Church there is no salvation. Now.. the Church also declares that while we know where the Church is, we do not know where it is not. In other words, there may be Christians outside the visible Orthodox Church who are members of the Church but in ways we do not know. It is really not our business nor perogative to make such judgments upon these other Christians.
Regarding salvation of those outside the Church, St Theophan the Recluse says: ""You ask, will the heterodox be saved... Why do you worry about them? They have a Saviour Who desires the salvation of every human being. He will take care of them. You and I should not be burdened with such a concern. Study yourself and your own sins... I will tell you one thing, however: should you, being Orthodox and possessing the Truth in its fullness, betray Orthodoxy, and enter a different faith, you will lose your soul forever."