How we cite our quotes: (Line)
Quote #1
[…] it must be remembered that we are in the preliminary stage of one of the greatest battles in history, that we are in action at many other points in Norway and in Holland, that we have to be prepared in the Mediterranean, that the air battle is continuous and that many preparations have to be made here at home. (17)
Churchill has to set the scene for this struggle between good and evil, which he does by reiterating the existing conflict and the seriousness of the coming war. The war is on England's doorstep at this point.
Quote #2
We have before us an ordeal of the most grievous kind. We have before us many, many long months of struggle and of suffering. (21-22)
Part of characterizing yourself as the good guy is a sense of victimization. You're suffering either because of unfair persecution, or, in this case, in order to protect the free world from fascism. Churchill wasn't wrong; the British (and everyone else) endured a lot of suffering at the hands of the Nazis.
Quote #3
You ask, what is our policy? I will say: It is to wage war […] to wage war against a monstrous tyranny, never surpassed in the dark and lamentable catalogue of human crime. (23-24)
Churchill's description of Nazi Germany (really the other Axis powers weren't the focus) illustrates how the British saw their enemy as truly evil. It goes way beyond a difference in political opinion or a territorial dispute.