PatG
I've played "How Beautiful" before for a wedding when I was a teen, and consider it fairly easy, but that's perhaps because I play by ear, and my genesis of playing piano was mostly based on simple, pop/contemporary church sort of chords.
If you're aspiring to play more "complexly" of modern contemporary christian music, I wouldn't recommend classical as the way to go, and instead focus on music such as Michael W. Smith, Chris Tomlin, those sorts of progressions. Think songs like Chris Tomlin's My Chains are Gone (Amazing Grace) etc.
That said, if you're interested in interesting chords, in the classical genre, I've found Rachmaninoff's Piano Concertos 2 & 3 to be quite fun [the third movements]. Warning, they're quite arduous at first to figure out. Simpler ones would be Chopin's Nocturnes. Easiest would be things like Canon in D (Pachelbel), and contemporary-classical like any Yiruma music.
Or Beethoven Moonlight Sonata movement 1. I reckon most musicians who have an intermediate or above recognition of basic chords can figure that one out pretty straightforward (albeit it'll take some time). Or Bach Prelude in C Major.
As this is my area I enjoy (e.g., I recently played random parts from all of the above, in all 12 keys, yet can't read almost anything on a sheet), I hope you find some of the suggestions above helpful.