John Main says that as we say the mantra we are putting into practice that injunction, ‘set your mind on God’s kingdom’. There’s trust in that, there’s faith in that. This is one of the essential experiences that becomes conscious in the course of learning to meditate and practising it – that we realise that in saying the mantra we are indeed placing our trust, putting our trust, entirely in the ground of our being, which for want of a better word we call God. So the mantra is not a technique but it is actually an act of faith. More than an act of the will, it is an act of our whole being, which becomes this fundamental trust in the divine nature and in our own capacity to share in that divine nature.
( Enlightenment by Laurence Freeman OSB )