In no uncertain terms had God commanded Israel to be His royal priesthood (Ex 19:5–6), to be His servant and His witness (Is 40–53) and to show forth His praises among the nations (Is 43:21). Later Christ speaks of His people as the salt of the earth and the light of the world (Mt 5:13–15). Israel was a peculiar, singular people with a glorious calling and mission (Deu 7:6; 14:2; 26:18–19).
The divine calling was accompanied by tremendous divine graces and enrichings. These, in turn were matched by equally weighty responsibilities. Somehow the world’s religious fate was bound up with Israel’s faithfulness and self-giving. Their calling demanded more than animal sacrifices. It required the dedication of the nation to the service of God for the welfare of the world.
Peters, G. W. (1972). A biblical theology of missions (pp. 109–110). Chicago, IL: Moody Press.