Question

The division of christianity emerged when a catholic monk questioned the selling of indulgences and began preaching

Answer 1

Protestant Reformation.

Step-by-step explanation:

Martin Luther was a Catholic monk that wrote "The 95 Theses", (which later became the foundation of the Protestant Reformation), after questioning and disagreeing with the sell of indulgences by the Catholic Church to people as a promise of God's forgiveness.

In the "95 Theses" Martin Luther stated that God wanted believers to have faith, and that faith is the path to salvation while good deeds are a result of this salvation and not the path as Catholics believe.

Answer 2

Martin Luther in 1517 in his “Ninety-Five Theses”, which he ceremoniously posted on the door of the All Saints' Church in Wittenberg, stood for the justification by the faith alone. His belief that salvation is a free gift of God’s grace that comes trough the faith in the figure that redeemed mankind from sin, Jesus Christ, put Luther at odds with the Pope who advocated the selling of indulgences as way of clearing oneself from sin.