A while back I wrote of my impression of the simplicity of God. I felt oddly affirmed when I read that Messiaen had expressed something similar.
“You are so complex and so simple, you are infinitely simple.”
In many senses this seems to be a mystical approach to God. However within faith I don’t think intellectual doctrine is antithetical to mysticism. I think both affirm each other and feed each other and it will be a mistake to put them up against each other.