Here is a sample that includes what I think is the central koan of the Christian religion:
Those who want to save their life will lose it, and those who lose their life for my sake will save it.
-- Jesus (Mark 8.30)
With the relinquishing of all thought and egotism, the enlightened one is liberated through not clinging.
-- The Buddha (Majjhima Nikaya 72.15)
Both of these teachings are about the imperative of letting go if we want to be whole and free.