Background: The Bible speaks of sheep and lambs, and 'other sheep', both of
which are apparently Christians. Jesus said "and other sheep I have,
which are not of this fold. Them also I must bring, and there shall be one
fold, and one shepherd of the sheep."
Q: who are the other sheep?
We already know they are Christians, but 'not in the fold'.
Q: which fold?
A: it is said in commentaries that the reference to other sheep is to the Gentiles.