One of the hardest things we have to learn is the extent of our own capabilities. Several factors come into play: our strength, our health, our understanding, timing, circumstances, and the countless variables inherent in other people in the midst of whom we are called to do our ministries. It is with full awareness of his limitations [probably health issues] that St. Paul hears the words of Christ spoken in his ear "My grace is sufficient for you, for my power is made perfect in weakness" [2 Corinthians 12:9].
The bedrock of all spiritual grace is the essential helplessness that we share as human beings. Psalm 88, one of the glummest psalms in the entire Psalter, has three spiritual truths that lay a new foundation. v. 4b "I am a man who has no strength," v. 8b "I am shut in so that I cannot escape." v. 12:c, and "I am helpless." Time and again we will come back to this starting place; the acknowledgement of our essential helplessness before God and humbly surrender to Him, who loves us so that He surrendered all, that we might be complete in Him. Only from that starting place can we go forward. While we are not called to go forward in our own strength, we are called to go forward in His strength. What He demands of us is sometimes more, and sometimes less than what we demand of ourselves. This is where healthy authority relationships can come into play. We are not always the best judge of our own capabilities.
St. Benedict writes:
“If it happens that difficult or impossible tasks are laid on a brother, let him nevertheless receive the order of the one in authority with all meekness and obedience. But if he sees that the weight of the burden altogether exceeds the limit of his strength, let him submit the reasons for his inability to the one who is over him in a quiet way and at an opportune time, without pride, resistance, or contradiction. And if after these representations the Superior still persists in his decision and command, let the subject know that this is for his good, and let him obey out of love, trusting in the help of God.” Chapter 68 Rule of St. Benedict
God is more clearly aware of our limitations than we are and often challenges us above what we think our limitations will allow. Often he will do that through those who exercise godly authority over us. He does this in part that we might learn to lean on Him and not on our own strength, and also in part that we might grow in grace and competence through the power of His Spirit with us.