I have a minor interest in physics, and read dumbed-down popular science books and articles aimed at "the layman".
One of the fascinating developments in physics in the last century or so is a greater understanding of "quantum physics", in which scientists are beginning to understand how things work on the smallest of scales. And what they have found is that on those very small scales, things get quite strange.
There's the famous experiment with the "double slit". This video explains it. One of the spookiest discoveries is that when light is not being measured or observed directly, it acts like a wave, but then when it is being observed, it appears as a particle. It's as if the particle "knows" it's being watched and changes its behavior accordingly.
I've found that quantum mechanics provides some helpful analogies to our life of good works as Christians.
We know that all Christians have faith, and that faith always produces good works. But we humans like to measure things, especially our own good works. And here's where things start to get strange. Here I think about the double-slit experiment. Our good works are like that photon in this way - when we observe them, things change! When we start looking at our good works and measuring them, especially against the perfect and holy standard of God's Law, they begin to look not-so-good after all. They are tainted and corrupted by sin, pride, false motivations, impure motives, etc. This is the "lex semper accusat", always accusing aspect of the law at work. When we look at our works, they appear as filthy rags - especially the closer we look.
So when the sheep and the goats are separated (Matthew 25), the sheep are quite surprised to hear of their good works. For they weren't busy looking at them. "When did we feed you, Lord? When did we clothe you, visit you?"
Scripture assures us that our faith DOES produce works. But it would not have us sit around admiring them. Rather, our focus should be on the cross of Christ (keep our eyes fixed on Jesus, the author and perfecter of our faith) and on the needs of our neighbor.
To the extent that we do good works, thanks be to God who gets the credit for them anyway. To the extent that we do good works, however weak and failingly, thanks be to God who accepts them through Christ nonetheless.
In Christ, we see perfect works - no matter how much of a magnification we put on the scope. In Christ, there is no uncertainty, but always blessed assurance that what he has done is enough, and is good enough. The resurrection proves the sufficiency of his life and death for us.
Then there's the Heisenberg Uncertainty Principle, which "any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known simultaneously."
In other words, there's always stuff we not only don't know, but there's stuff we can't know.
But Christ is the certainty principle of God. He sends his Spirit, who creates faith in us, and that "faith is the assurance of things hoped for and the conviction (certainty) of things unseen". Hebrews 11:1 Christ's promises to us about forgiveness today and resurrection on "that day" are surer than any observation. For though even our eyes may fail us, he never will. And though what we see may or may not be, he assures us, "before Abraham was, I am".