[OBW]

I went to public schools as well. And I had to learn some things much later in life.

One short comment: For the verses that mention something (as opposed to a feeling, etc.) that is called "spirit" (presumably something to do with us, therefore legitimately a "human spirit") determine what the writer is getting at.

Example 1: In Hebrews (where it speaks of the two-edged sword), it is speaking about the fact that God sees more than we can. Even sees the separation of joints and marrow (something 1st-century man didn't really see or understand), and of soul and spirit. But the point wasn't to figure out what the difference in soul and spirit is, but rather to admit we don't know what the difference is and understand that God does. He can judge the attitudes and thoughts of the heart — something that would be required if he is to then grant a "sabbath rest," which is what the passage is discussing.

Example 2: "The Lord be with your spirit." Is the need to understand how it is that the Lord is with us, or to understand that he is with us. Said another way, the verse declares that the Lord is with us. That is a fact. Even if the reference to "spirit" was not made, it would be true. That fact is not diminished by the lack of the reference. Nor is it increased if we think we have all the understanding of what the "spirit" is.

So, this raises a question. Does the use of the term "spirit" in any verse that appears to be referencing some aspect of the human being need an explanation of what "spirit" is for us to appreciate the intent of the verse or passage? If not, then unless it seems to be spelled out somewhere, maybe we don't need to dwell on it.