According to the Zen records it is useless for practitioners to aim for a reified (imagined, envisioned) concept of ‘enlightenment’ or ‘Buddha’ – anyone that is not here-now enlightened or here-now Buddha must be here-now deluded or here-now ordinary; anything they ‘envision’ or ‘imagine’ will be off the mark. Thus Dogen says:
When we perfectly realize it, while still as we are, we would never have thought previously that realization would be like this. Even though we had imagined it, it is not a realization that is compatible with that imagining. Realization itself is nothing like we imagined. That being so, to imagine it beforehand is not useful.
Yui-butsu-yo-butsu, Gudo Nishijima & Mike Cross
The point, then, is that practitioners need to recognize delusion as delusion. Enlightenment is one possible form of activity (reality), and delusion is the other possible form of activity. To be deluded is to be ‘fashioned by activity’ (to be ‘turned by the sutra’, to be the ‘subject of causation’); to be enlightened is to be the ‘fashioner of activity’ (to ‘turn the sutra’, to be ‘causation’ itself).