[Titanites]

I maintain there were always a core set of people in the western church that understood the concept of unmerited grace. Some of our Orthodox and Catholic friends would say this isn't so, that Luther invented the whole thing.

Yes, the core set of people were Catholics (and by this term I include the Orthodox). Luther didn't invent unmerited grace. From the Cathechism of the Catholic Church:

1996 Our justification comes from the grace of God. Grace is favor, the free and undeserved help that God gives us to respond to his call to become children of God, adoptive sons, partakers of the divine nature and of eternal life.

Free and unmerited.

[kosta50]

Free and unmerited

Correct. The Church never taught "unmerited grace." The difference is created and uncreated grace, but that's a whole different topic and has nothing to do with merit.