Help me understand John Coltrane .... seriously.

As a Davis / Coltrane fiend, I second a lot of the advice on easing into Coltrane through the First Great Quintet years (55-58).  Workin is my fave of the Prestige recordings. Kind Of Blue speaks for itself. I’d suggest one other approach: the Thelonious Monk/Coltrane works, which were in the same period (56-57).  The Monk&Coltrane The Complete Riverside Recordings are available on CD for about $10... a easy intro.  Thelonius Monk With John Coltrane is about $10 on CD as well. The T. Monk Quartet with Coltrane at Carnegie Hall is a nice extra.  Monk was a significant influence on both Davis and Coltrane, and (IMO) his focused approach to bebop is a wee bit like Coltrane’s focused approach to free jazz. Once Coltrane left Davis, his early work is the most accessible.  Blue Train and Soultrane don’t get the same attention that Giant Steps and Lush Life do.  Coltrane Plays The Blues is a good listen. Anything after A Love Supreme gets...challenging. Both Directions At Once and Blue World are kinda the bridges to ALS.  Ascension is an acquired taste.  In all, Coltrane’s evolution is a lot like Davis’ - at a certain point, the WTF factor sets in for me. YMMV.  Bin voyage!

For what it is worth, I had the same experience and mentioned it to a composer friend....he simply explained that JC was simply looking for God....changed everything for me

I would recommend starting with Soul Eyes or After the Rain.  I feel if neither of those grab you then perhaps it's something that just isn't your thing.  Best to spend your time listening to things you like, no?

Check out some Sun Ra 

With Coltrane... You either get it or you don’t his music moves you, takes you to a different place, I’ll leave you confused. Sit in the dark listen to love supreme and you’ll get it