Wash yourselves, make yourselves clean; remove the evil of your deeds from My sight. Cease to do evil, learn to do good; seek justice, reprove the ruthless, defend the orphan, plead for the widow. Come now, and let us reason together, says the Lord, though your sins are as scarlet, they will be as white as snow; though they are red like crimson, they will be like wool. If you consent and obey, you will eat the best of the land; but if you refuse and rebel, you will be devoured by the sword. Truly, the mouth of the Lord has spoken. (Isaiah 1:16-20)

“There is a delicate balance to be maintained here between human freedom and divine sovereignty. On the one hand, it ought not to be said that obedience produces forgiveness. God forgives and cleanses not because he must, but because he wishes to and has made a way for that to be done through the death and resurrection of Christ. But, on the other hand, it is also plain that God does not proclaim forgiveness to those who are unwilling to obey. All the rhetorical language of the prophets, urging people to obey, is in opposition to any position that God’s forgiveness can ever be experienced apart from a disposition to obey him.” (Oswalt, John N. The Book of Isaiah, Chapters 1–39. The New International Commentary on the Old Testament. Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1986, 102.)