At the still point of the turning world

From Ash Wednesday by T. S. Eliot

If the lost word is lost, if the spent word is spent

If the unheard, unspoken
Word is unspoken, unheard;
Still is the unspoken word, the Word unheard,
The Word without a word, the Word within
The world and for the world;
And the light shone in darkness and
Against the Word the unstilled world still whirled
About the centre of the silent Word.

via Ash Wednesday by T. S. Eliot.

(“The still point of the turning world” is from Eliot’s “Burnt Norton,” the Four Quartets.)

What is Eliot saying about the Word?  about the Word in an age of unbelief?  What does this have to do with Ash Wednesday and the beginning of Lent?