英语翻译Since our chief business with them is to enable them to

这是一个复合句.Since our chief business with them is to enable them to share in a common life 是since引导的原因状语从句,we cannot help considering whether or not we are forming the powers which will secure this ability是主句,其中which will secure this ability是定语从句,修饰先行词powers.
因此,断句如下：
Since our chief business with them is to enable them to share in a common life既然我们的主要任务在于使他们参与共同生活；
we cannot help considering whether or not we are forming the powers我们禁不住考虑我们是否在形成这种力量；
which will secure this ability获得这种能力的.
句子翻译：
既然我们的主要任务在于使他们参与共同生活,我们禁不住考虑我们是否在形成获得这种能力的力量.