I would agree that discipline, cultivated in a wholesome way is helpful, though after many years of meditation and study I have seen "doctrine" to not always be helpful.
At this point in my understanding or more accurately the understanding that is happening, I wonder if we inadvertently create a false dilemma for the individual with religious ideas.
Specifically does one need a doctrine to cultivate humility, patience, and the ability to look deeply?
Perhaps many do and that is fine as far as it goes.
Growing up in rural Pennsylvania I remember wandering through pastures and forests, along streams and rivers and to my childs mind and heart I could be nothing but humbled by the wonder of it all, I spent hours sitting quietly, listening and watching life around me.
This happens even now when I go for walks or just sit looking out my window.
Back then I didn't have any religion or ideas of philosophy, I just was and experienced being as it is.
When I first heard Suzuki refer to "things as it is" I knew what he meant.