Proverbs 16:18 Pride goes before destruction, and a haughty spirit before a fall.
Galatians 6:14 But far be it from me to boast except in the cross of our Lord Jesus Christ, by which the world has been crucified to me, and I to the world.
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.