Here's some Chaos chants/prayers/catechisms from various places.
"Who pledged his loyalty?
The Warmaster
Whom did we serve in faith?
The Warmaster
From whom did we take our name?
The Warmaster
Who was denied to us?
The Warmaster
But whom shall we remake?
The Warmaster
And who shall lead us to victory?
The Warmaster" Black Legion Catechism
I'll add more later, when I find that damned Codex Chaos. [2nd Ed - those thing are fluff bibles!]