If you allow yourself to become full of pride, eventually you will find yourself humbled.
Like many other much used expressions this one has its roots in the Old Testament Book of Proverbs. In this case Proverbs 16:18
Pride goes before distruction, a haughty spirit before a fall.
Other nearby verses in Proverbs offer additional reminders that wisdom and modesty are to be preferred over pride and wealth:
How much better to get wisdom than gold, to choose understanding rather than silver. (v16)
The highway of the upright avoids evil; he who guards his way guards his life. (v17)
Better to be lowly in spirit and among the oppressed than to share plunder with the proud. (v19)