"The pride of thine heart hath deceived thee..." (Obadiah 1:3)
Unchecked, pride does not stagnate; it proliferates. And it only becomes more audacious with age. It worms its way into our character and holds us with the chains of self-importance (Psl. 73:6).
Pride is not always easy to recognize—in ourselves or others. As Andrew Murray said, it often "clothes itself with humility." It can be disguised as other, more acceptable, traits. For instance, there is an obsessive, break-neck "Christian" service that is really a neurotic bid for praise (Matt. 23:5a). And sometimes, people who would lead you to believe they are highly principled, are just plain stubborn. Many a so-called leader is just someone who is sure he or she knows what is best for everyone else and is determined to make them aware of it!
It is not the overtly proud individual (i.e., the haughty braggart) that is the most dangerous, I think, but rather the one who covertly draws attention to himself or herself by inconspicuous, subtle maneuvering. These are the ones who bring contention (Prov. 13:10) and leave destruction in their wake (Prov. 16:18).
You and I would be well advised to dig up the seeds of pride in our lives, lest they take root and turn into weeds of ruination.
"Pride makes devils out of angels." (Isaiah 14:12)