As long as the green mountains remain, one need not worry about firewood.

The core meaning of this sentence is that as long as the most fundamental and crucial things are still there, there is no need to fear the lack of development opportunities in the future.

Here, "Qingshan" usually refers to the person themselves (such as health, life), or core resources and fundamental abilities; "firewood" represents specific benefits, goals, or outputs. Even if "firewood" is temporarily lost, as long as "Qingshan" is still there, there is a chance to recreate it.

In simple terms, it emphasizes preserving the fundamentals and leaving room for maneuvering, which is more important than getting caught up in the gains and losses of the moment. For example, when facing difficulties, ensure your safety and core capabilities first, as this creates the possibility for a turnaround later.