Lord God,

You are the greatest and holiest mystery.

Be all of my love,

all my hope,

all my striving;

let my thoughts and words flow from you,

my daily life be in you,

and every breath I take be of you.

– St John Cassian 360-435AD.  Also known as John the Ascetic, or John Cassian the Roman.  He learned from Christian monks in Egypt and brought writings and theology of a simple direct and anti-materialist flavour to the wider Christian movement.