His reply was, “Yes! This is the explanation I have been longing for! Thank you!” Perhaps others also have been looking for it. So, here goes —–
His original question was “I have thought that Jesus preached both law and grace. But, am I mistaken?” The following was my “answer / explanation.”
Since your question has various embodied topics and nuances, I’ll limit my comments, hoping they will help. First, you are correct; Jesus affirms the legitimacy of both grace and law in the Kingdom of God, with the caveat that we properly understand of the purpose of law.
The Law verbalizes, or concretizes, Kingdom of God behaviors, values, and commitments. It establishes standards; it portrays Kingdom normalcy. But, the Law is also multilayered, with some laws arising from underlying laws. “Love your neighbor” is an underlying law, with many specific laws arising from it. Picture the layering of laws as an upside down pyramid, with love at the base. Then specific commands build up from that base in layers. For example, there was a very specific law in the Old Testament requiring the Jewish folk to put a protective edging around the roof of their house to keep people from falling off. The ultimate basis of this specific law ( located at the top level of the inverted pyramid) is the underlying (base) command to love.
The specific laws are binding on God’s children as long as the context pertains. Said differently, specific laws contextualize deeper laws to the living human conditions at particular times and places. This same situation is the case in both the New and Old Testaments, no matter who the author or the speaker is (Jesus, Paul, James, John, etc), because it is simply the nature of Law. Parts of Jesus’ Sermon on the Mount command basic law, and other parts of said Sermon command specific applications of the basic laws. There are terms for this situation. Basic laws are “apodictic” laws. Specific laws, which are the basic laws applied to specific situations, are referred to as “casuistic” laws (case laws).
Law’s function is not to spiritually “save”(regenerate) anyone. Humans are regenerated anywhere and anytime, by God’s grace. Law tells us the rules of the road. Grace restores us from the consequences of violating the rules of the road. This can be fleshed out considerably, but you can handle that :).
Living in God’s Kingdom requires both law and grace. On one hand, we need to know the “rules” of the Kingdom. On the other hand, we need to “brought into” the Kingdom from our status of being out of the Kingdom.
The Old Testament is full of grace. Think of David in the Psalms who repeatedly portrays God as the Responder to the sinner (the one who is paying the consequences of not living the rules of the Kingdom). Has anyone ever been saved by works (doing the law-described behavior) before, during, or after the time of Jesus? No. It simply is not the function of the Law to save anyone.
Law has its purpose; Law has its results. Those are two different things – Purpose and Result. The Law’s purpose is to guide humanity in a life that conforms to God’s will for humanity. The Law’s Results include our being guilty of law breaking, which hopefully will drive us to God’s grace. But, the purpose of the Law is not to make us sinners. That is a result of the Law.
Let me conclude by encouraging all Christians to value God’s law for what it truly is and does, but not expect it to do what is not its purpose. That false expectation leads to frustration and judgementalism. Law shows us how to live. Grace saves us from not living according to the law. Grace and law are not in competition; it is not a case of having one or the other.