Psalm 10:4 explains that the proud are so consumed with themselves that their thoughts are far from God: “In his pride the wicked does not seek him; in all his thoughts there is no room for God.”

Psalm 10:4

In the pride of his face the wicked does not seek him; all his thoughts are, “There is no God.”

This kind of haughty pride is the opposite of the spirit of humility that God seeks:

“Blessed are the poor in spirit: for theirs is the kingdom of heaven” (Matthew 5:3).

The “poor in spirit” are those who recognize their utter spiritual bankruptcy and their inability to come to God aside from His divine grace. The proud, on the other hand, are so blinded by their pride that they think they have no need of God or, worse, that God should accept them as they are because they deserve His acceptance.

Why is pride so sinful? Pride is giving ourselves the credit for

something that God has accomplished. Pride is taking the glory that belongs to God alone and keeping it for ourselves. "What do you have that you did not receive? And if you did receive it, why do you boast as though you did not?" (1 Corinthians 4:7). That is why we give God the glory—He alone deserves it.

2 Corinthians 10:17 - 18 (NLT)

17 As the Scriptures say, “If you want to boast, boast only about the LORD.”

18 When people commend themselves, it doesn’t count for much.

The important thing is for the Lord to commend them.