Problem: Some interpreters argue that the prophets believed that Israel could stop sinning and clean up their act on their own. Here, Isaiah commands, “Learn to do good; seek justice, reprove the ruthless, defend the orphan, plead for the widow” (Isa. 1:17). Some interpreters call this Pelagianism (i.e. humans can choose good or evil without divine help). Is this the case?
Solution: The Bible teaches that God has common grace for those who do not know him. For instance, James writes, “Every good thing given and every perfect gift is from above” (Jas. 1:17). Jesus taught that God “sends rain on the righteous and the unrighteous” alike (Mt. 5:45). Therefore, when we see great acts of love and sacrifice, this is due to the prevenient (or common) grace, which God gives to all people. For this reason, we should not interpret these commands apart from God’s grace –but through it.
In addition, we need to interpret this passage in light of God’s provision spelled out in the very next verse. Isaiah continues, “‘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” (Isa. 1:18). Isaiah has just finished explaining the corruption and injustice in Israel. Here, he says that they will be completely forgiven in their entirety. Imagine what a shock this would be to them! The Jewish readers must have been confused about this, but remember what God said: “Let us reason together…” In other words, Isaiah must have wanted them to think how this could be logically possible. Of course, throughout the rest of the book, Isaiah goes on to explain how the Servant will come and make this possible through his death on the Cross (Isa. 42, 49, 50, 53). Therefore, Isaiah might already be setting up the readers for the conclusion he will reach in chapter 53.
