with their heartfelt beliefs.
Zen wants the mountains to stay where they are.
It is not the task of Zen to rearrange the mountainside.
-Unknown author.
James: I take this as teaching us not to fight up stream nor to fight against nature. Like the temple pictured above we need to work with nature, not destroy it. They don't try and dominate nature they simply build their temple in compliment to it. I also think it is talking about avoiding arrogance when discussing Buddhism with non-Buddhists. No one wants to be preached to about how "Enlightened" you profess to be regardless of your progress along the path. That refers to the verse about "moving mountains." Perhaps we might think or say, "I feel so 'enlightened' that I could move mountains!!"
That's spiritual greed wrapping itself around our practice like a boa constrictor does. The ego-mind is a powerful thing and loves to keep us entertained with delusions of grandeur attempting to use greed as a way to maintain the feeling of "self" and self-importance. It's easy for the ego/mind/self/voice that's in the back of our thoughts to believe, "It's o.k. to be greedy about status as long as it's status as a Buddhist" or "I'm not being mean. They just don't understand how "enlightened" or practiced I am."
So with this ego-mind we sometimes try to convince everyone else to become Buddhist or to remind others that they're not doing such and such as exactly how the Buddha taught in the Tripitaka. It's not the business of Zen or our personal business to try and move people toward what we we personally might think (with a heartfelt belief as the verse above says) is how they should practice Buddhism. The mountains move only when they want to move just like people. It is not our task to proselytize door-to-door as missionaries for Buddhism. It is equally not our task to be the Dharma police.
Leave people be, leave the mountains where they are. As the saying goes, "When the student is ready, the teacher will appear." A person has to come to Buddhism of their own commitment for it to mean anything authentic and to see any meaningful progress. Rearranging the deck chairs on the titanic didn't keep it from sinking and constantly drilling someone in the ears with the Dharma over and over isn't going to keep them from falling away from Buddhism if their heart isn't in it. As I said, mountains only move when they want to move. In order for the Dharma to be sincere in our lives and in the lives of others it has to evolve for each person in their own time.
UPDATE: I wanted to add an addendum to expand a bit upon an aspect to this discussion that
Lorem Ipsum brought up in the comment section about being open to sharing the Dharma but not until others are ready and approach us about it. It's a further explanation of what I wrote above. I thought it was an important thought that I had overlooked a bit in the post. I'd add my own twist to it by saying that I talk about Buddhism a bit with non-Buddhists but very sparingly and not in-depth unless questions are asked of me. If people want to know about it then I will gladly discuss it with them but as the verses say it's not our job to move mountains. I usually won't go into any great depth unless someone asks specific questions about Buddhism and what it means to be a Buddhist. I try and emphasize that I'm not an ordained teacher or Dharma scholar. So when my knowledge is exhausted I urge them to seek out a teacher and read books if they have further questions. Especially books from ordained, experienced masters like Thich Nhat Hanh, Ajahn Chah or the Dalai Lama.