A Dr Jim Fenhagan, an Episcopalian from the U.S.A., told this story in a presentation I heard many years ago in Melbourne, and it has stayed with me and guided me.
An old man sat by the flooded Ganges river in India. He noticed a scorpion float down the river and get caught up in the roots of a tree on the side of the river. The scorpion would drown in the rushing, rising current. The old man reached down to save the scorpion. The scorpion arched its back and stung him on the arm. Again the man reached down his arm, but again he was stung. This continued several times. A young man standing nearby said,"You stupid old man! Why do you continue to try to help that ungrateful creature?". As the old man reached down again to save the scorpion, he replied, "Just because it is his nature to sting, that is no reason I should change my nature to save." Jim Fenahagan said, "To understand that story is to understand the cross of Christ, and the way of Jesus."
It is a story that still inspires me.