The word "gentile" is used in the Bible as a translation for goy. A goy is someone who is not a descendant of Jacob. Wasn't the New Testament written in Greek, as opposed to Hebrew for the Old Testament? If so, can you identify the word that was translated to "gentile" by James? I'd do it but I don't have access to a Strong's.
Is "goy" a Hebrew word, a Yiddish word, and if Yiddish, was the source Hebrew/Aramaic or some other root, like Germanic? Lots of different roots make up Yiddish.
I think the important part was to "go unto the Lost Sheep of The House of Israel", which of course must be the descendents of the House of Israel.
Wasn't the New Testament written in Greek, as opposed to Hebrew for the Old Testament? Yes, but Jesus spoke in Aramaic (a language related to Hebrew), not Greek. He would not have said "gentile." The word Jews use that is translated as gentile is "goy," which refers to the nations descended from Noah, as listed in Genesis.
Is "goy" a Hebrew word, a Yiddish word, and if Yiddish, was the source Hebrew/Aramaic or some other root, like Germanic? Lots of different roots make up Yiddish.
Yiddish is not the source of anything. Yiddish is a Germanic language which Jews began to use in Eastern Europe in medieval times. It includes many Hebrew words, one of which is goy. The word goy is Hebrew and it appears in the Hebrew text of the Old Testament.
I think the important part was to "go unto the Lost Sheep of The House of Israel", which of course must be the descendents of the House of Israel.
It could mean that. It could also mean those who have lost faith.