Wrong application of the word pride. In the bible verses you quote it is used in the sense of ‘an air of superiority or self-sufficiency’.
Being proud of a child, or of a job well done, or of a church are all used in the sense of “acceptance of something pleasing or wholesome in one’s life”. So, if someone recognizes the wholesomeness of their denomination, then one would think they’d want to share how they’ve received that gift.
Of course.......
Please show where the concept of "denominations" was taught by the apostles that we should understand their "wholesomeness".