Once again we begin Torah, happily anticipating those old familiar stories that we learned as kids: the creation, Adam and Eve, Cain and Abel. Too bad no one showed us the introductions to Genesis where commentators posed questions for adults.

For instance, the Ramban — master of Torah, science, philosophy, and mysticism — wonders if all knowledge is knowable. He cites the talmudic tradition that God’s creation holds 50 measures of knowledge, all but one delivered to Moses. A 50th measure remains hidden forever from human beings. God alone knows it, and we cannot be God.

Now we understand why God forbade eating from the tree of knowledge. The issue is not at all straightforward. On the face of it, God says that the tree promised knowledge of good and evil. But Adam and Eve had to know good from evil already or there would have been no such thing as “disobedience” for God to punish. What could the forbidden fruit have added to the elementary human conscience with which even Adam and Eve were born?

There is a difference between what we think is good and evil and what God knows to be the case. Only God can solve, forever and for sure, intransigent moral dilemmas: Is capital punishment permitted? How about abortion on demand? What are the ethics of war? On these and similar issues, we stake out moral claims, but only God knows with certainty what the moral answer is.

Our primal parents knew more than we ever will — Adam named the animals and Eve conversed with snakes. But they wanted more. The tree of knowledge, they figured, held the final 50th measure: certainty. On matters moral — and who knows what else — eat its fruit and be like God!

That was their sin: imagining they could know it all — and be God.

Modern physics underscores the futility of such a hope. The building blocks of our universe are subatomic particles, about which we can know either their position or velocity, but never both — we can know where a particle is, but by the time we know it, it isn’t there any more; or we can know how fast it is moving, but not where it began and where it will end up. The more we know about the big picture, the more detail eludes us.

God’s 50th measure of knowledge turns up elsewhere too. Deuteronomy 29:28 announces, “Secret things are God’s; revealed things are ours and our children’s.” Most commentators think the secret things are crimes that people successfully hide even from the law but not from God, who will punish them later. Ramban, however, opines, “These ‘secret things’ are sins of which even the people who do them are unaware.”

We are limited not only in our knowledge of outside phenomena; we cannot even know everything about ourselves.

Limits to our knowledge crop up everywhere. Life and death themselves are mysteries — Why is there life at all, and why eventually does all life perish? What is the nature of time, let alone eternity? What makes things beautiful? Why do bad things happen to good people? Is there a soul? Almost 3,000 years of Eastern and Western philosophy combined haven’t nailed these questions successfully. Some contemporary philosophers warn us to give up on them. But still we wonder. How can we not?

When the Talmud does not know something, it frequently holds the question open, announcing teiku — which later generations read as the acronym, “The Tishbi [Elijah] will [some day come and] resolve all outstanding questions.” So maybe we get to know it all (like God) in the world to come. But the Talmud has a second answer that applies to the here and now. Im ein r’a’ya ladavar, yesh zeher. “If there is no proof of something, there may at least be a pointer [to its truth].” The ultimate truths reserved only for God carry hints of their reality. Unable to transcend human limits and know for sure, we sometimes bump up against these hints, pointing us toward the realm of spiritual wonder and linking us to the divine.

For 25 years, I have asked people to describe experiences they found spiritual. Almost invariably, they report glimpses across the limits of knowing: clutching a newborn, holding hands with a parent at the moment of death, saving a life, standing in Jerusalem in the maelstrom of Jewish time, stopping for a sunrise or the infinite complexities of a single flower. When pushed, people may identify these as moments when they knew God was present.

God did us a favor by forbidding the tree of knowledge. Knowing it all would have eradicated wonder. We ought to value not just what we know but what we don’t. I don’t mind waiting for Elijah for some things. But meanwhile, I look for glimpses of eternity.