Romans 2:28
2:28 For a person is not a Jew who is one outwardly, nor is circumcision something that is outward in the flesh,
Romans 14:5
14:5 One person regards one day holier than other days, and another regards them all alike. Each must be fully convinced in his own mind.
Romans 15:20
15:20 And in this way I desire to preach where Christ has not been named, so as not to build on another person’s foundation,