all-important
all important
crucial ***
essential ***
of the essence

He had work to do, and time was of the essence.

The idea that information and order are part of life's essence has been with us for 2,000 years.

Bush Administration officials said that they felt time was of the essence.

What you were talking of - the essence behind the form.

Now that they were inside, time was of the essence.

For the person behind the camera, movement is also of the essence.

As time is of the essence, I will come straight to the point.

Time is of the essence: his treatment must begin immediately.

To do that, time is of the essence, they say.

As you have pointed out, time is of the essence.