There are three A.A. Big Book references to a broad spirituality.
1) “We feel we are on the Broad Highway, walking hand in hand with the Spirit of the Universe.”– AA Big Book, pg.75 (bold mine)
2) “We found that God does not make too hard terms with those who seek Him. To us, the Realm of the Spirit is broad, roomy, all inclusive; never exclusive or forbidding to those who earnestly seek. It is open, we believe, to all men. When, therefore, we speak to you of God, we mean your own conception of God.”– AA Big Book, pg.46-47 (bold mine)
3) “If our testimony helps sweep away prejudice, enables you to think honestly, encourages you to search diligently within yourself, then, if you wish, you can join us on the Broad Highway. With this attitude you cannot fail. The consciousness of your belief is sure to come to you.”–AA Big Book, pg. 55 (bold mine)
Yet, this is just what Christ warns us about:
“Enter through the narrow gate; for the gate is wide and the way is BROAD that leads to destruction, and there are many who enter through it.” (Matthew 7:13)
The AA Big Book is basically the AA “bible,” and millions of people have gone down the broad way of destruction because of such teaching.