1. A proud Christian will seldom, if ever, admit to actual sin. He might talk about sin in the abstract, "sin" as a doctrine or a concept, but it's often deflected out onto the "world", as if evil is always external to himself. In extreme cases, he might hold to a doctrine of sinless perfection, or claim the sin-nature can be eradicated in this life. Some Christians talk too much about their sins, sometimes to a squirming degree of unwanted detail. But, to the proud person, admitting actual sin is humiliating. Proud people seldom, if ever, admit to needing daily forgiveness. Ecclesiastes 7:20.
2. A proud Christian seldom, if ever, admits to needing help. Self-reliance is taken to an extreme, sometimes a harmful extreme. Even though the Bible tells us to carry one another's burdens (Galatians 6:2), which implies a degree of weakness in all of us, the proud man or woman won't accept help, or even admit needing it. This is because because admitting weakness is embarrassing. It reveals them to be less than what they want to believe about themselves, or want other people to believe about them.
3. A proud Christian wants to control, but at the same time habitually rejects authority. Like arrogant Diotrophes (e John 9-10), he is driven by a desire for the preeminence, but he also rebels whenever authority is applied to him. He wants accountability for others, but never wants it for himself. The proud Christian chafes against not being obeyed.
4. A proud Christian resents other Christians' gifts, positions, or accomplishments. Like Saul becoming jealous of David's victories (1 Samuel 18:8), the proud person sees other Christians' achievements as a personal slight. The other person's victories diminish them, in their own eyes. They feel threatened by people who are better than they are. The reverse of this was John the Baptist, who was content for Jesus Christ's fame to grow as his own fame diminished (John 3:30).
5. Using Saul is a pride-indicator, pride leads to a paranoid perspective. Saul's jealous resentment over David's victories immediately led Saul to convince himself that David was scheming after the throne. There was no evidence that David had that in mind. Saul was "projecting" what he would do were he in David's shoes. This can happen because the heart is deceitful (Jeremiah 17:9); the proud heart lies to itself first among all.