This chapter focuses on the wonderful love God has for His people. Amazingly, even though human sin has corrupted the future God had promised, His words will not return void. Given the current exile as well as the horrific past sins of Israel, it would seem impossible that God could actually deliver on His past promises to this nation. Just considering the words to Abraham alone seem completely unrealistic.
But He is God and He cannot lie to His people. Just as God could make a barren woman miraculously bear a child, He could rescue us from our sinful past and crown us as heirs to His Kingdom. Not only that, but He could put His Spirit inside these broken vessels to proclaim His greatness and majesty to all people.
This is really the characteristic of God that has overshadowed all of the filthy decisions of mankind. We are completely helpless, just as a barren woman, but He comes in His grace and makes a way. Through His compassion and His incredible mercy, God makes a way for us. It makes no sense. All we can do is praise and worship Him.