Help me understand John Coltrane .... seriously.

To keep it simple, Coltrane on Atlantic is easier on the ears than the later material on ABC/Dunhill/MCA. In music theory classes way back when, the tune Spiral off of Giant Steps was offered an an example of defining a physical shape/attribute with sound. If you like that, the rest of the album should interest you, followed by the My Favorite Things album.

One must appreciate the history of half century old jazz to get these artists.  From the same time period, I simply don't get doo-wop, country and western, old rock and roll, or any smooth jazz that arose from this AM car radio era.
My boy did learn to like Coltrane and Miles, despite his phishheadenness, but don't wory about it, especially on streaming devices.  The selection that gets streamed is based on algorhythyms that pander to what is listened to by the most idiots.Additionally, my appreciation of these old jazz artists is that they make great, low level, party background music, if you like old Broadway show tunes, plus of course their importance in the history of jazz for white people. 

Coltrane is very challenging, and though I have always liked him - especially his 1961 Village Vanguard performances - I never understood him. This Vox Explainer actually does a terrific job of breaking down what Coltrane is doing and why:

https://youtu.be/62tIvfP9A2w

Believe it or not, what helped me getting started with jazz of his style after many listenings without enjoyment is I got high once and went on a concert in Velvet lounge in Chicago. From then on, loved it.
 

What is it you are trying to understand?

Ask yourself what is it you understand about another genre?

Dont try and understand Jazz.

Your sort of non connection to Coltrane just means its outside of your taste for listening.

How many Yanni or Nana Maskouri albums do.you own?

So what if you dont dig Coltrane.

Move on.