Revelation 16:10-11:

And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain.
And blasphemed the God of heaven because of their pains and their sores, and repented not of their deeds.

Notes on Revelation 16:10-11:

Let those who think that God sends plagues, sores and calamities to draw people closer to Himself consider this – it’s not a reliable method!  The people in this passage were made sick, but that sickness did NOT result in repentance!  It is the goodness of God that leads men to repentance (Romans 2:4).

See also:

Notes on Romans 2:4
Sickness as Chastening and Judgment in the New Testament
Objection: God Uses Sickness to Draw Us Closer to Himself
Objection: God Uses So-and-So Powerfully Because She Was Paralyzed When She Was Young
Condition: Sores