Perhaps everything you say is true and these are the death throes of the human race, but even if that was true, I would not lose faith. There must be hope, and I must fight for my Emperor against Chaos and it's servants. That is insanity. Wrong, it's being human.

— Ben Counter

We do not know what our chances of survival are, so we fight as if they were zero. We do not know what we are facing, so we fight as if it was the dark gods themselves. No one will remember us now, and we may never be buried beneath Titan, so we will build our own memorial here. The Chapter might lose us and the Imperium might never know we existed, but the Enemy — the Enemy will know. The Enemy will remember. We will hurt it so badly that it will never forget us until the stars burn out, and the Emperor vanquishes it at the end of time. When Chaos is dying, its last thought will be of us. That is our memorial — carved into the heart of Chaos. We cannot lose, Grey Knights. We have already won." ~Justice Alaric

— Ben Counter