Evil is an odd word. It often gets used for all sorts of things we dislike, though I would like to reserve it for truly horrific violations of human dignity (bombing civilians or using food as a weapon or depriving the poor of the medical care others receive). Some things truly are evil, and we need to name them. You can’t adhere to the good unless you know and avoid the evil.
How do we know which things are evil? Psalm 36 takes on that question. It describes itself as an “oracle” (Hebrew: ne’um; v. 1), a label that usually shows up in the books of the prophets. (Many translations obscure the Hebrew word here.) Perhaps we should think of it more as a meditation of a prophetic kind. In any case, the psalmist paints a sharp contrast between the person whose mind focuses only on evil and the God who focuses only on the good.
In a text reminiscent of such intense moral reflections as Job 29-31 or even the Sermon on the Mount, the psalmist speaks of one about whom it can be said
There is no dread of God before his eyes, for he uses his eyes to divide up things for himself [i.e., is always calculating personal gain] to find his iniquity in hatred. The words of his mouth are folly and contentiousness. He quits thinking about the good. He thinks about folly when he lies down, he stands in the not-good way. He does not reject evil.
The business of lying and standing reminds one a bit of Psalm 1, and this psalm illustrates what the earlier one means by the “wicked.” There is a human character that is so self-absorbed that it can only focus on its own good. Such a focus leads to the destruction of social bonds, the crushing of the vulnerable, and soon even the destruction of the soul of the wicked person himself or herself. Sometimes we can repent of such an approach to life, but sometimes we become enmeshed in it that repentance becomes a practical impossibility.
Now the contrast. Unlike other psalms, this one does not appeal to an ideal human type (often embodied in the composer himself!) but to God. First come several images of permanence and knowability. Yhwh’s “steadfast love” is in the heavens, righteousness is like the lofty mountains (Hebrew: har’re-El or “mountains of God”), judgment is like the great abyss etc. Not only is God’s loyalty to human beings unshakeable, it is known by everybody. And it is comprehensive, for “you save human and beast.” In the astonishing moral world of God, even animals can expect deliverance from their foes, at least in appropriate ways!
The most influential verse is perhaps v. 9: “For with you is the fountain of life; in your light, we see light.” That line has graced the seal of Columbia University for over 200 years, for example. But the verse’s influence probably comes from its elegant way of saying two important things. (1) God brings life to all things, not just in the sense of originating everything, but in the sense of giving everything purpose and meaning in relationship to everything else. And (2) God sends illumination to human beings so that we can understand those purposes and the providential care behind them. Because God gives light, we can distinguish between good and evil, not just as a disembodied set of principles, but as expressions of these very same relationships. And the ability to make such a distinction is the necessary precondition of our acting in favor of one and not the other. In God’s light, we see light. And it is beautiful.