"The will is a beast of burden. If God mounts it, it wishes and goes as God wills; if Satan mounts it, it wishes and goes as Satan wills; Nor can it choose its rider... the riders contend for its possession"

This quote by Martin Luther is a metaphor for the power of free will. He is saying that free choice resembles a beast of concern, because it can be controlled by either God or Satan. It has no option in who its rider is, and the 2 riders, God and Satan, are in consistent competitors for its belongings. Luther is suggesting that free will is an effective force, and that it is eventually approximately us to decide who will be its rider. He is saying that we have the power to select between God and Satan, and that our options will identify our destiny. Eventually, Luther is stressing the importance of exercising our free will in order to make the ideal choices and lead a life of purpose and significance.