Romans 15:8

Now I say that Jesus Christ was a minister of the circumcision for the truth of God, to confirm the promises made unto the fathers:

Jesus Christ became a minister to the circumcision, to the Jews, for the truth of God, to confirm and make sure the promises made to the fathers and forefathers, thereby upholding God's truth and faithfulness. That ministry to Israel opened the way for the Gentiles to glorify God for His mercy, so that Jews and Gentiles rejoice together with God's people. In the closing days this is fulfilled when Jews come into the ranks of God's chosen followers, are numbered with the Israel of God and are once more reinstated with the people of God, while the Gentiles rejoice with them and the blessing of the Lord rests richly on all who enter that rejoicing.

His work toward people never finds fault with them but only sets before them and lays before them the dangers from which He wants to deliver them. Fitness for service following His example as minister depends on sanctified mental power, sanctified brain-power, and sanctified talent of speech. This places solemn responsibility on God's commandment-keeping people to stand as lights in the world, reflecting rays of light on the pathway of those who do not keep God's commandments, seeking to be light-bearers and shining as light-bearers in whom divine truth appears and shines distinctly through words and works.

As they let their light shine, men see their good works and glorify God, even the Father in heaven, a precious saving influence goes forth, and they must keep their light constantly shining. Among themselves no quarreling or backbiting or dissension is to be seen. Those who look to Him must keep their eyes fixed on Him and follow Him by guarding the door of their lips, refusing to speak or listen to criticism and faultfinding, speaking kindly and tenderly, meeting harsh words and provocation with silence, and confessing their own sins and humbling their hearts before God, because a quarrelsome, faultfinding spirit will never enter the city of God.