Martin Luther and the Idea of Grace
Of the many reformers involved in the Lateran Council, the one whose proposals for change would become the most influential was in 1517 an unheard of monk named Martin Luther.
Luther was typical of a monk in the period. He was born the son of a merchant, who sent him to a university and intended for him to enter the legal profession. However, the intense young Luther had a "conversion experience" a moment when he suddenly felt an intense fear that he would not achieve salvation. In response, he decided to become a monk, so he could pray and contemplate how God must decide who is saved, who is condemned.
The Catholic Church had traditionally taught that all people were born sinners naturally, but that by following the teachings of the Church leaders and by engaging in holy acts known as sacraments notably confessing sins, doing penance, and performing charitable works anyone could gain salvation.