Martin Luther believed the use of indulgences was wrong. To be forgiven, people need to pray and change their behavior.
Luther didn't believe that the pope had the authority to forgive people who were already dead.
If only there was a quicker way to do this.....AHHHA I have a idea.
His also condemned church officials for excessive gambling and drinking, and challenged them to lead moral lives.
Indulgences was a practice where the church certified your soul would enter heaven more quickly by reducing your time in purgatory. If you committed sins you stayed in purgatory until you can make them up.
The invention of the printing press greatly impacted the Reformation. The printing press allowed ideas to spread more rapidly. This also made printed products more affordable.
The outcome of Martin Luther challenging the Catholic Church was two major groups in Christianity - Protestant and Catholic.