Those who hope in the Lord will renew their strength

Isaiah 40:1-31
A voice of one calling: “In the wilderness prepare the way for the Lord; make straight in the desert a highway for our God, Every valley shall be raised up, every mountain and hill made low; the rough ground shall become level, the rugged places a plain. And the glory of the Lord will be revealed, and all people will see it together. For the mouth of the Lord has spoken.”
All people are like grass, and all their faithfulness is like the flowers of the field. The grass withers and the flowers fall,  but the word of our God endures forever.”
Say to the towns of Judah, “Here is your God!” He tends his flock like a shepherd: He gathers the lambs in his arms and carries them close to his heart; he gently leads those that have young.
Why do you complain, Jacob? Why do you say, Israel, “My way is hidden from the Lord; my cause is disregarded by my God”?
He gives strength to the weary  and increases the power of the weak. Even youths grow tired and weary, and young men stumble and fall; but those who hope in the Lord will renew their strength. They will soar on wings like eagles;   they will run and not grow weary, they will walk and not be faint.
Isaiah 40-50 addressed these dispirited exiles. Although god has punished them - as he had so often warned, and as they deserved - he still loves them. They can trust him. He has the power to help them and fulfill his promises.
These chapters are so full of hope and comfort that they are known as "The Book of the Consolation of Israel". They also look far beyond the circumstances of Israel in the 6th century BC. Where the previous chapters spoke of a future king, these speak of a coming 'Servant' who will carry out God's purposes at great cost. The New Testament, with Christians ever since.
This whole section speaks so powerful of God's salvation that Christians see in it something much bigger than the rescue of Israel at a particular time in history. Here is God's firm purpose to deliver humankind from the 'bondage' of sin: his promise of a new life for all who will come to him.
Why?
There is comfort for God's people in their distress: he is coming as he promised. Israel's God is the Creator: incomparable, eternal. Yet he never stops caring for his people.
Everyone before the Lord is nothing, like grass, their faithfulness is like the flowers of the field, but the word of our God endures forever. Every man is so small and little, faith of men are weak and limited. But the word of God endure forever. What God's said will be done.
No matter what distress or upset we are,  turn to the Lord. Those who hope in the Lord will renew their strength.