A tumor and swelling in the mind

(Thomas Brooks, "The Unsearchable Riches of Christ")

"The Lord Almighty has done it to destroy your pride
 and show His contempt for all human greatness."
    Isaiah 23:9

Pride is the original and root of most of those notorious
vices which are to be found among men.

Of all sins, pride is most dangerous to the souls of men.

Pride is . . .
  a gilded misery,
  a secret poison,
  a hidden plague.

Pride is . . .
  the conceiver of deceit,
  the mother of hypocrisy,
  the parent of envy,
  the moth of holiness,
  the blinder of hearts,
  the turner of medicines into maladies.

Of all sins, spiritual pride is most dangerous, and must
be most resisted. Spiritual pride is the lifting up of the
mind against God; it is a tumor and swelling in the
, and lies in despising and slighting of God—and in
the lifting up of a man's self, by reason of birth, breeding,
wealth, honor, place, relations, abilities or graces—and in
the despising of others.

Spiritual pride is a white devil, a gilded poison—by which
God is robbed of his honor, and a man's own soul of his
comfort and peace.

Pride is a sure forerunner of a fall. "Pride goes before
destruction, and a haughty mind before a fall."
Herod fell from a throne of gold—to a bed of dust.
Nebuchadnezzar fell from a mighty king—to be a beast.
Adam fell from innocence—to mortality.
The angels fell from heaven—to hell; from felicity—to misery.

"The day is coming when your pride will be brought low
 and the Lord alone will be exalted. In that day the Lord
 Almighty will punish the proud, bringing them down to
 the dust!" Isaiah 2:11-12

"The Lord detests all the proud of heart. Be sure of this:
 They will not go unpunished!"  Proverbs 16:5