This is from The Practice Of The Presence Of God - Letters
http://www.practicegodspresence.com/
--------------------
Eleventh Letter: I do not pray that you may be delivered from your pains; but I pray earnestly that God gives you strength and patience to bear them as long as He pleases. Comfort yourself with Him who holds you fastened to the cross. He will loose you when He thinks fit. Happy are those who suffer with Him. Accustom yourself to suffer in that manner, and seek from Him the strength to endure as much, and as long, as He judges necessary for you.
-------------------
The Eleventh through the Fifteenth letters are very good regarding suffering.

Disclaimer: I don't necessarily agree with his theology but think he has a lot of good things to say.