An ancient Zen master said that zen is like learning archery; only after long practice do you hit the bullseye.
Enlightenment is experienced instantaneously, but Zen work must be done over a long time, like a bird that when first hatched is naked and scrawny, but then grows feathers as it is nourished, until it can fly high and far.
Therefore those who have attained clear penetrating enlightenment then need fine tuning.
When it comes to worldly situations, by which ordinary people get suffocated, those who have attained Zen get through them all by being empty. Thus everything is their own gateway to liberation.
Set aside all the slogans you have learned and all the intellectual views that stick to your skin and cling to your flesh. Make your mind empty, not manifesting any thoughts on your own, not doing anything at all. Then you can attain thoroughgoing Zen experience.
But even when you reach this point, you should still realize that there is progressive action that transcends a teacher.