8 Remember that Christ came as a servant to the Jews to show that God is true to the promises he made to their ancestors. 9 He also came so that the Gentiles might give glory to God for his mercies to them. That is what the psalmist meant when he wrote: "For this, I will praise you among the Gentiles; I will sing praises to your name."
Matthew Henry's Commentary on Romans 15:8-9
Commentary on Romans 15:8-13
(Read Romans 15:8-13)
Christ fulfilled the prophecies and promises relating to the Jews, and the Gentile converts could have no excuse for despising them. The Gentiles, being brought into the church, are companions in patience and tribulation. They should praise God. Calling upon all the nations to praise the Lord, shows that they shall have knowledge of him. We shall never seek to Christ till we trust in him. And the whole plan of redemption is suited to reconcile us to one another, as well as to our gracious God, so that an abiding hope of eternal life, through the sanctifying and comforting power of the Holy Spirit, may be attained. Our own power will never reach this; therefore where this hope is, and is abounding, the blessed Spirit must have all the glory. "All joy and peace;" all sorts of true joy and peace, so as to suppress doubts and fears, through the powerful working of the Holy Spirit.