What is the difference between the following two sentences.
There was not a moment to be lost.
There was not a moment to lose.
There is no significant difference in meaning. The "to be lost" form is slightly more formal, and perhaps a bit more old-fashioned, but neither would seem odd in current speech, I think. Yet more informal would be
There was no time to lose.
This is not quite as forceful -- "not a moment" emphasizes that not even the smallest bit of time could be spared.