My friend Margaret, writes:
"What do I say to my dear Muslim friends? You need to be converted before you are saved? They already lead lives which are in every practical respect Christian. We never disagree over values, over the way to bring up our children, over how others should be treated, over the role of women. They are some of the people I most respect in the world and truly good people. Largely because of this impossible conundrum I drifted away from a church which demands that we make those who profess other faiths into outsiders."
Many years ago, when I was a 19 year old brassy Marine, home on my first leave, I was emptying the contents of my seabag on the bed in my room looking for a pair of jeans to wear. As I was doing this my father walked in and noticed a book on the bed which he picked up out of curiosity. It was a copy of The Book of Mormon which another Marine, who happened to be a Mormon, had shoved into my hand before I left. I wasn't even remotely interested in reading it, but so as not to embarrass this guy, I held onto it. My Dad leafed through it, looked at me with disappointment written all over his face and asked "Why are you reading this?" I quickly assured him that I had no intention of converting to Mormonism. What he said surprised me. "Only God knows what is in our hearts and only he can judge us, but be careful about what you read, hear and say." He put the book back on the bed and walked out. We never talked about it again.
Since then I have thought a lot about what he said that night. My Mormon buddy probably thought I was going straight to Hell, with no rest stops in between, he saw it as his duty to straighten me out, especially in light of my "strange" religious preference. I could tell my Dad thought these guys were out in left field but he didn't come right out and say it. I never figured out why my Dad, a devout Orthodox Christian, failed to come down hard on those of other faiths. Perhaps Dad knew a little more about the subject than I did. When I read the passages below in an extraordinary book entitled "Gifts of the Desert: The Forgotten Path of Christian Spirituality" by Kyriacos Markides (pp. 154-156), the light bulb in my head suddenly went on, finally after so many years. In the book, Markides asks some tough questions of Metropolitan Kallistos Ware, a truly remarkable Orthodox prelate and theologian, who is, by the way a countryman of yours. He is really worth getting to know better:
"It is not for us to say who is saved or is not saved. God is the one who decides that. And we do not have the right to say to any particular person that he or she is not saved. We do not know. As to how people are saved, we know for certain that it is only through Christ, the unique only begotten Son of God. But Christ can act in different ways: sometimes explicit, sometimes hidden. My own belief is that, bowing before this mystery, nonetheless we may say: If a Muslim, a Hindu, a Buddhist or a Jew has lived according to the highest and best in their tradition, then in some way they already believe in Christ because all truth is in Christ.'
....You are saying then that such people are Christian, as it were, in their inner being, and not Christian in any culturally recognizable way. Rather they manifest Christ as the Logos which is God's love. So persons who express that love are Christian deep down. It is the degree to which humans can express love that determines to what degree they come close to Christ. 'This is what I believe.'
...'Many Christians who in this life thought they believed in Christ may find, when they meet Christ after death, that he says to them: 'I do not know you! You are not my servants. You used my name but you were not close to me.' So, we cannot say that you will automatically be saved just because you happen to be a member of the Church, and we cannot say that you will automatically be condemned simply because in this life you did not belong to the Church.'
Quoting from St Augustine, Bishop Kallistos added: 'There are many wolves inside and many sheep outside."
Hope this helps you as much as it helped me.
P.S. Regards to your friends.
P.S.S. Hear him for yourself, here.