How do you turn weakness into strength?

How to convert weakness into strength?

Keep the balance in your mind—God has nothing, but compassion and understanding, yet it is not in His power to interfere with the quest of the spirit—with the free will of the individual. That spirit has chosen certain experiences—and if in the process, the physical betrays, then the spirit, of necessity, goes back on its tracks again and again until the weakness is turned into strength.