The principle of weakness is unique. It means helplessness. God is saying that when you are weak or suffering, His grace is overwhelmingly sufficient for you. His grace is designed to take over your weakness.
Even though you feel powerless or without energy in your soul, His grace is adequate. God does not ask us to have strength. He does not demand performance. He does not tell us to achieve certain works. He is teaching us how grace functions perfectly in our weakness. Grace enters into the flow of our heart and reveals the power of the Word of God in action, within the mentality of the soul. God may be speaking to our heart, saying, “I give to you a grace that is of me. I have been satisfied by the payment for your sins by my precious Son. I am satisfied that you believe in Him by faith, and I give you my righteousness without works.”
In Romans 11:6, God gives us a supreme definition of grace: “And if by grace, then it is no more of works: otherwise grace is no more grace. But if it be of works, then it is no more grace: otherwise work is no more work.”
Stop and listen as if God were saying to you, “When you are suffering with heartache and sorrow, my grace is overwhelmingly adequate for you.”