Thomas Aquinas, after a life in spent crafting his Summa Theologica in which he aimed to answer the question of God’s purpose for creation and in what ways we are to exist in it, died having declared his philosophical works useless compared to a beatific vision he had later in his short life.

Schopenhauer, too, devoted roughly 500,000 words to describe the Will, this thing that no words can capture. But he further claimed the sacred writing of the Upanishads to have been the solace in his life as well as in his death.
There is a lot of ink spilled trying to describe the ineffable.
Writer, philosopher and composer Roger Scruton describes the experience of reading a book Music and the Ineffable by Vladimir Jankélévitch. It’s a book he describes as ‘mercifully short.’ But not short enough, actually:
[Jankelevitch’s] “argument is stated on the first page — namely, that since music works through melodies, rhythms and harmonies and not through concepts, it contains no messages that can be translated into words. There follows 50,000 words devoted to the messages of music — often suggestive, poetic and atmospheric words, but words nevertheless, devoted to a subject that no words can capture.”
Music does seem to be a chrysalis for disclosing the ineffable. Driving home the other night I heard the Kronos Quartet’s version of “The Fly-Freer,” a haunting tone poem written by Sigur Rose for an Icelandic avant-garde rock group, arranged for strings by Stephen Prutsman.
Driving through the darkness, hearing the strings swirl and spiral, and shriek and whisper—and of course, they weren’t doing any such things; there were no shapes to see, no voices to hear—I had one of those moments. You know those moments. Something is being told to you. You don’t know what it is. You don’t know the teller. You don’t need to know either.
To paraphrase Shakespeare, the experience is all.