These chapters particularly address the questions of whether God could deliver and whether He wanted to deliver the Israelites that the coming exile raised in the minds of Isaiah's contemporaries.
"We emerge in 40:1 in a different world from Hezekiah's, immersed in the situation foretold in 39:5-8, which he was so thankful to escape. Nothing is said of the intervening century and a half; we wake, so to speak, on the far side of the disaster, impatient for the end of captivity. In chs. 40-48 liberation is in the air; there is the persistent promise of a new exodus, with God at its head; there is the approach of a conqueror, eventually disclosed as Cyrus, to break Babylon open; there is also a new theme unfolding, to reveal the glory of the call to be a servant and a light to the nations."388
Isaiah's audience was not in Babylonian captivity when he wrote these chapters. He was prophesying about the people of God in that captivity. Chapters 40-66 presuppose the Exile.
"In these chapters the prophet reminded the people of their coming deliverance because of the Lord's greatness and their unique relationship with Him. He is majestic (chap. 40), and He protects Israel and not the world's pagan nations (chap. 41). Though Israel had been unworthy (chap. 42) the Lord had promised to regather her (43:1-44:5). Because He, the only God (44:6-45:25), was superior to Babylon He would make Babylon fall (chaps. 46-47). Therefore Isaiah exhorted the Israelites to live righteously and to flee away from Babylon (chap. 48)."389