What Actions Led Martin Luther To Break Away From The Catholic Church?

On October 31, 1517, Luther nailed ninety-five theses regarding indulgences on the church door at Wittenberg, Germany. This was the practice in his day for publishing a challenge for a debate. No one accepted his challenge and no discussion of the subject with church officials ever occurred.
Thesis number five said: "The Pope has neither the will nor the power to remit any penalties, except those which he has imposed by his own authority, or by that of the canons." Thesis number twenty-one stated: "Thus those preachers of indulgences are in error who say that, by the indulgences of the Pope, a man is loosed and saved from all punishment."
By thus challenging the church's practice of selling indulgences, Luther unwittingly launched himself on the road to separation from the Catholic church and struck the spark that ignited the Reformation. His theses were translated from Latin to German and printed by some of those who read them. They became a common topic of conversation throughout Germany.