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 I cannot find, either in Scripture or history, a strong-willed individual whom God used greatly until He allowed him to be hurt deeply.
It was just such a person who wrote these words for all to read:

Guests
Pain knocked upon my door and said
That she had come to stay,
And though I would not welcome her
But bade her go away,
She entered in.
Like my own shade
She followed after me,
And from her stabbing, stinging sword
No moment was I free.
And then one day another knocked
Most gently at my door.
I cried, "No, Pain is living here,
There is not room for more."
And then I heard His tender voice,
"'Tis I, be not afraid."
And from the day He entered in,
The difference it made!
---Martha Snell Nicholson

Insight for Living"