Then he will know his good servants... and his enemies

Gandalf:

I have come for your aid Saruman the White, in troubled times. The Nine are abroad, darkness approaches, the Black Riders! Saruman:
Is that all the news you have for me then? Gandalf:
Is that not enough? Sauron is moving at last! Saruman:
We can deal with Sauron ourselves Gandalf. You, and I. One way or another. Gandalf:
What talk is this? What are you saying Saruman? Saruman:
It is time for us to choose. A new age is upon us, a new power is rising. Nothing that Elves or Men or Wizards can do will avail against it. Its enemies are utterly doomed, but its friends... Gandalf:
You are saying that we should join with Mordor? With him? Saruman:
Does that displease you? Where is the Ring Gandalf? Why do the servants of Sauron seek for it in the Shire? Have you hidden it there? Would you rather see the Dark Lord have it, or Saruman of Many Colours? Gandalf:
Neither of you will have it. Saruman:
There is a third choice. It is to remain here, until you tell me where the One Ring may be found. Gandalf:
Saruman, if you do this, if you delay me here, Sauron will surely get it then. Saruman:
Then he will know his good servants... and his enemies