Isaiah 5:20 Link to LXE
The Fourth Woe
Woe to them that call evil good,
and good evil;
who make darkness light,
and light darkness
who make bitter sweet,
and sweet bitter. (LXE, Brenton)
The core idea, or theme, that binds the three clauses of this verse is “reversal.” It is also helpful to know that the Greek word for “evil” is “πονηρός,” approximately pronounced, “pony-ross.”
The New Testament verse that comes to mind in comparison with this verse is Matthew 6:23–
“but if your eye is bad (πονηρός), your whole body will be full of darkness. If then the light in you is darkness, how great is the darkness!” (ESV)
Let’s shine the light of Isaiah 5:20 upon Jesus’s statement in Matthew 6:23. God intends the human eye to be a very good feature. When the eye functions properly, light floods a person with great understanding regarding the world around them. When the eye malfunctions, it’s as though the person is surrounded by darkness.
Metaphorically, the eye of our understanding is the lens through which we view the moral qualities of the world. If the basis, or lens, of our understanding is faulty, our conclusions about what is good and what is bad in the world will also be faulty.
Another verse that bears on this topic is Matthew 20:15. In this verse, Jesus speaks in a figure which ties together Isaiah 5:20 and Matthew 6:23. It does so on both a linguistic and a conceptual level–
Matthew 20:15 `Is it not lawful for me to do what I wish with my own things? Or is your eye evil (πονηρός) because I am good?’ (NKJ)
To paraphrase, I think Jesus, who takes the part of the vineyard owner (who represents God), is saying something like this: I own the vineyard. That means that I am the boss here. I know that I am good, and I only do good things. I know that my paying some of my laborers a generous amount is a good action. You other laborers see my good action as though it were bad, even though I did not cheat you in any way. The problem lies not with my actions of generosity, but with your faulty understanding of them. Because you see my good as though it were bad, your eye must be bad (or, evil.)
Some of the newer translations substitute the figure in the literal Greek with an English figure that they feel will be easier for readers to understand.
Matthew 20:15 Am I not allowed to do what I choose with what belongs to me? Or do you begrudge my generosity?’ (ESV)
Matthew 20:15 Am I not permitted to do what I want with what belongs to me? Or are you envious because I am generous?’ (NET)
The NET Bible does include a translator’s note for this verse, “Is your eye evil because I am good?” That is the literal translation of the Greek. The words used are very close to Isaiah 5:20. However, for the sake of perceived clarity, these newer translations lose the linguistic and conceptual connections with both Matthew 6:23 and Isaiah 5:20.
An Alternate Reality–Alternate Facts 
What are Isaiah and the Lord Jesus saying with these verses about an “evil eye,” turning light to darkness, and darkness to light? First, a caveat–being physically blind or having poor sight does not make anyone evil in a moral sense. Nor does this condition cloud one’s judgment of what is right and what is wrong.
In a physical sense only, not being able to see is a loss that must be compensated. Light is an inestimably marvelous reality. By means of light reflecting off objects, we see the physical world around us, including color. We see how the world is laid out in front of us. We read a person’s face to determine their state of mind, emotions, and intention.
The eye is the instrument that receives the light. The light is translated by our nerves and brain into information. Without the eye and the light that it receives, a person lacks a vast quantity of information about the world around them.
I cannot help but see the political scene of America in 2020 with regard to this verse in Isaiah. Not intending to choose sides, the current stage of disagreement concerning what is real and what is truthful, is staggering. Two church persons can look at the same event and one sees evil while the other sees good. The viewpoints are often so extremely different that it appears they can’t both be right.
The example Jesus gave is a good one. The landowner in Matthew 20 gave extra money to some of his laborers, but not to all of them. The landlord cheated no one, he kept his word, he lived up to his end of the bargain which he made with the workers he hired first. Nevertheless, he treated some of the workers with great generosity.
To certain of the laborers, this generosity was bad. Why was it bad? They saw it as bad simply because they weren’t the recipients. But Jesus identifies this as faulty thinking. Their underlying assumption is wrong. The landowner sums up the situation, “Is your eye evil because I am good?”
It pays to dig into the question of what about their underlying assumption is wrong. By using this parable of the kingdom, Jesus identifies the issue of a bad heart. A morally diseased heart interprets the world incorrectly. It would be like a physical eye that malfunctions, one that cannot receive and interpret the light correctly. Darkness dominates.
So Let’s Dig
Sin is like a disease. It causes severe malfunction. The first example of an “evil,” malfunctioning eye is the eye of Satan. Satan has a bad heart. He views his position in God’s creation incorrectly.
Satan is a created, angelic being. He was the highest, most beautiful of God’s angelic host. Satan fell in love with himself instead of with God, his creator.
Severe problems began when Satan began comparing himself with God’s Son, whom we know as Jesus the Christ. God’s Son is himself very God of very God. Satan, as a created being, could never come close to the three-in-one godhead in terms of glory. This aroused his jealousy, just as those laborers were jealous of the landowner’s generosity toward others. Satan wanted to be the exalted one. He “wanted to live alone upon the land,” (Isaiah 5:8, LXE).
Cain’s heart was also bad. His moral eye was diseased. He interpreted God’s favor toward his brother as a bad thing, not as the good thing it was. God warned Cain of the bad path he was on (Genesis 4:6-7). He encouraged Cain to change the sacrifice he was offering (vs 7). Cain could have done so. He could have gone to his brother and asked for an animal to sacrifice to the Lord. He could have made it work out. But Cain chose to be the only one. He murdered his brother. He persisted in seeing himself, his brother, and God incorrectly.
Keep Digging: How Is Jesus Different?
Jesus God’s Son is different than both Satan and Cain. He sees himself and the Father with a good eye.
Philippians 2:3 Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. 4 Let each of you look not only to his own interests, but also to the interests of others. 5 Have this mind among yourselves, which is yours in Christ Jesus, 6 who, though he was in the form of God, did not count equality with God a thing to be grasped, 7 but emptied himself, by taking the form of a servant, being born in the likeness of men. 8 And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. (ESV)
Jesus is different because, “though he was in the form of God (i.e., very God of very God himself) did not count equality with God a thing to be grasped, but emptied himself… he humbled himself.” Neither Satan nor Cain chose this path. It’s because their underlying understanding of God’s creation and their role in it was faulty. Their eye was “evil,” or “bad.”
So What Is Isaiah’s Accusation Here?
Quite simply, God through Isaiah accuses his “beloved plant” (vs 5:7), his household Israel, of having a bad heart. The bad heart causes the eye, the moral center of interpretation, to malfunction. The malfunction causes Israel to see everything upside down. Good becomes evil; evil becomes good; light becomes darkness, darkness is considered to be truth. A bitter taste is thought to be sweet, and a sweet taste bitter.
What Is the Antidote?
Isaiah delivered these words to the people of his nation to give them opportunity to repent. God always gives us two choices: we can agree with him or not. For those who choose to continue in disagreement with God, unfortunately for them, he is God, and they are not.
God created the world good, just as he planted a good vineyard with a good vine in Isaiah 5:1-7. But the world and the vineyard became bad. God’s grace corresponds to the generous employer in Jesus’s parable of the kingdom, Matthew 20:1-16, which we explored above. Those who choose the pathway of God’s grace (which of necessity includes grace to others) will return to a good world and a good vineyard. Those who choose to continue in their own pathway, God will remove, just as he removed Israel from the land he had given them.
Please, if you haven’t done so already, please choose the pathway of God’s grace.
Postscript
Here are some further verses that bring the lie to the people Isaiah describes in 5:20. In God’s reality, good remains good, and bad remains bad.
Matthew 7:17 So, every healthy tree bears good fruit, but the diseased tree bears bad fruit.
Matthew 7:18 A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit.
Matthew 12:34 You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks.