One of the fun things about preaching through a book of the Bible like Isaiah is the opportunity to learn famous verses in their context. Virtually every Christian that has read Isaiah 55:1 or heard it mentioned in church hears it as an invitation for non-Christians. The invitation, then, is for all of us to leave our worldliness behind (cf. Isaiah 55:7). Each week we’re all tempted to adopt the ways of the world as our ways, as the right way. Each weekend we come together and affirm our desire for our Lord (cf. Isaiah 55:6). Another famous verse is found in Isaiah 55:11. Whenever God’s call to repentance is announced, that word always accomplishes God’s goal. Those with ears that can hear in the Church hear God’s call and respond by forsaking their wickedness. You might make sense out of the chapter this way: 1. Our condition (vv. 1-2a). 2. God’s offer (vv. 2b-5). 3. Our reaction (vv. 6-11). 4. Our new condition (vv. 12-13). The main thing is to be sure that the offer in Isaiah 55:1 is connected to the instruction in Isaiah 55:7. Those who respond to the offer will one day inhabit God’s new world in Isaiah 55:12-13. Oh, and it’s all possible because our Lord experienced the thorns during His crucifixion. That is why we can purchase sustenance “without price” (cf. Isaiah 55:1). It’s free to us because it cost Him everything.