We are instructed to teach, and pray for, the lost sheep of the household of Israel/Jacob. The household of Israel/Jacob are made up of every kindred, and tongue, and people, and nation.
God blinded most of the house of Israel, his sheep, for their disobedience, in turning away from him, and worshiping idols however he left in the midst of them an afflicted and poor people that trusted in the Lord. The remnant of Israel shall do no iniquity, nor speak lies; neither shall a deceitful tongue be found in their mouth, for they shall feed and lie down, and none shall make them afraid. (Zeph 3:11-13).
The remnant of Israel is to teach the gospel to the lost sheep of the house of Israel, and pray for their repentance
Both, the house of Israel, and the remnant have the promise of an eternal inheritance.