It seems to me that in His own parable, Jesus counted as righteous the good deed done by the Samaritan, and again, Jesus was pleased with the Samaritan (whom He had cured), singling him out as the one of ten who was cured who came back to give thanks.
Jesus also promised “living water” to the Samaritan woman at the well.
In two of these instances,(one a parable and one a real happening) Jesus counted as righteousness the acts of the Samaritans; first for compassion, and second, for gratitude.
In the third, he reached out to a Samaritan. In all cases, as a Jew, he was supoosedly not to have anything to do Samaritans.
Yet He found rightouesness in a Samaritan.
God’s ways are not our ways.
Is that a “yes”?
But in each of those cases, just like in the OT saints and the stillborn baby and even in the bushman who has never heard the Gospel, it is still and always and only Jesus Christ who will save them, if God wills.
Not Mohammad. Not Buddha. And not their own righteousness, but the righteousness of Christ imputed to them.
And it doesn't look like that is the Gospel Mother Teresa preached.