Pain humbles the proud. It softens the stubborn. It melts the hard. Silently and relentlessly, it wins battles deep within the lonely soul. The heart alone knows its own sorrow, and not another person can fully share in it. Pain operates alone; it needs no assistance. It communicates its own message whether to statesman or servant, preacher or prodigal, mother or child. By staying, it refuses to be ignored. By hurting, it reduces its victim to profound depths of anguish. And it is at that anguishing point that the sufferer either submits and learns, developing maturity and character; or resists and becomes embittered, swamped by self-pity, smothered by self-will.
I have tried and cannot find, either in Scripture or history, a strong-willed individual whom God used greatly until He allowed them to be hurt deeply.
Charles Swindoll, Killing Giants, Pulling Thorns