Romans 15:1, 9

Now we who are strong [in our convictions and faith] ought to [patiently] put up with the weaknesses of those who are not strong, and not just please ourselves.

and for the Gentiles to glorify God for His mercy [to them, since God had no covenant with them]. As it is written and forever remains written, “THEREFORE I PRAISE YOU AMONG THE GENTILES, AND SING PRAISES TO YOUR NAME.” [Ps 18:49]