Like so many common verbs, the meaning of "know" in the Bible is varied and dependent on context. And in some cases -- when it is connected to ideas or objects -- its spiritual meaning and natural meaning are essentially the same. When the Bible talks about people knowing each other and especially when it talks about the Lord knowing people, the meaning has more to do with the states of love within people than it does with any factual knowledge. This makes sense if you think about it. When we really "know" somebody, what we mean is that we know what kind of person they are, what their motivations are, what they love, what they hate, what makes them tick. Those things are far more important than knowing their parents' names, where they were born or what year they graduated from school. Most often then, especially applied to people, "knowing" has to do with the perceptions we have about other people's loves and the conjunction that can exist between those with similar loves, not just a collection of facts.

In regular language, "mercy" means being caring and compassionate toward people in poor states. That's a position we are all in relative to the Lord, all the time. Without Him we would be unable to choose what is good; without Him we would be unable to formulate a reasonable thought. Without Him, in fact, we would instantly cease to exist; we have life only because He constantly gives us life. So we are, quite literally, at His mercy. Fortunately, the Lord is caring and compassionate to a degree we cannot fathom. He is the source of all caring and all compassion, and of love itself. His mercy toward us never lessens, never abates, never ends; His whole purpose is to bring each of us, individually, to heaven. The meaning of "mercy" in the Bible is closely tied to this idea: it represents love in a general sense, and the desire for good that comes from love. It can also represent the desire for good and the ideas that describe it when those thoughts and desires are inspired by love of the Lord.