Isaiah 40:25, 27-28
Our Thoughts of God
The first question here rebukes wrong thought about God. “Your thoughts of God are too human,” Luther said to Erasmus. This is where most of us go astray. Our thoughts of God are not great enough; we fail to reckon with the reality of his limitless wisdom and power. Put this mistake right, says God; learn to acknowledge the full majesty of your incomparable God and Savior.
The second question rebukes wrong thoughts about ourselves. God has not abandoned us anymore than he abandoned Jacob. He never abandons anyone on whom he has set his love. If you have been resigning yourself to the thought that God has left you high and dry, seek grace to be ashamed of yourself. Such unbelieving pessimism deeply dishonors our great God and Savior.
The next two questions and the statements which follow rebuke our slowness of heart to believe in Gods majesty. God would shame us out of our unbelief. He asks: Have you been imagining that I, the Creator, have grown old and tired? The rebuke is well deserved by many of us.