Pride is considered the most serious of the seven deadly (or capital) sins, as it is the root from which all other sins arise. It is a disordered love of self and a desire for one's own excellence that rejects submission to God and refuses to acknowledge one's status as a dependent creature (CCC 1866).
The Root of the Fall
The original sin of Adam and Eve was fundamentally a sin of pride—the desire to be "like God" but without God, before God, and not in accordance with God. Pride blinds the intellect and hardens the will against grace. The only remedy for the vice of pride is the cultivation of its opposing virtue: humility, which is the truthful recognition of our absolute dependence on the Creator (CCC 398, 2559).
May the Lord bless you and keep you.