From Carl H von Bogatzky

"Have mercy upon me, O lord, for I am weak.Psalm 6. 2. Strengthen thou me according unto thy word. Psalm 119. 28.  Divine Answer: My grace is sufficient for thee, for my strength is made perfect in weakness. 2 Corinthians 12. 9. The Lord delighteth not in the strength of a horse; he taketh not pleasure in the legs of a man. The Lord taketh pleasure in them that fear him, in those that hope in his mercy. Psalm 147. 10, 11. The Lord our Strength, mighty God and Immanuel, will give strength unto his people. Psalm 29. 11.

In whatever part we are weak, and most beset by corrupt nature, we may yet be strong enough, through grace, to come off conquerors; therefor, hope against hope; hope, and despair not of overcoming by the power of God, be thy corruptions within, and thy enemies without, ever so strong and obstinate. I am weak indeed, but Christ is strong; I am poor, he is rich; I am sick, he the Physician of the sick, I am a sinner, he is the Saviour of sinners; consequently, he suits me, and I suit him, extremely well. But let me look to him daily, seek his face earnestly, and grace to help in every time of need." (Carl H. von Bogatzky, The Golden Treasury)

Let me but hear my Saviour say, "Strength shall be equal to thy day;" Then I rejoice in deep distress Leaning on all-sufficient grace. I glory in infirmity, That Christ's own power may rest on me; When I am weak, the I am strong; Grace is my shield, and Christ my song. I can do all things, or can bear All sufferings, if my Lord be there; Sweet pleasures mingle with the pains While his left hand my head sustains.