If you want something you can have it, but only if you want everything that goes with it, including all the hard work and the despair, and only if you're willing to risk failure.
He meant the Kingdom was over, the Kingdom of Heaven, it was all finished. We shouldn't live as if it mattered more than this life in this world, because where we are is always the most important place.... We have to be all those difficult things like cheerful and kind and curious and patient, and we've got to study and think and work hard, all of us, in all our different worlds, and then we'll build... The Republic of Heaven.
It's only through honesty and courage that science can work at all. The Ptolemaic understanding of the solar system was undermined and corrected by the constant pressure of more and more honest reporting.