▲句子分析：

behold: 祈使句的谓语。

the power: behold 的宾语

of that: 介词短语作定语，修饰 the power

which is yet unborn: 定语从句，修饰 that。

▲语法说明：

当先行词是 that(指物)时，其后通常用 which 来引导定语从句。这样用的 that which 根据情况可以用 what, the thing that 等来替代。如：

She was prying into that which did not concern her. 她在打听与她无关的事。

They say the only real knowledge is that which can be measured. 据说唯一真实的知识是可以检验的知识。

It is part of human nature to be attracted to that which is aesthetically pleasing. 为令人愉悦的美的东西所吸引是人类的天性。

TheUnited Stateswill do that which is necessary to meet its obligations to its own citizens. 美国将为自己的公民尽其应尽的义务。

Too much time is spent worrying over that which one can’t change. 太多的时间花在了担心那些我们无力改变的事情上。

Indoor pollution falls into two categories, that which we can see or smell, and pollution which is invisible and produces no odour. 室内污染分为两种：一种是我们能看得见或闻得着的，另一种是无色无味的。