Why did catholics begin to questions roman catholics authority?

Catholics have started questioning The Roman Catholic Church during the Reformation.

Abuses within the Church marked the start of the Protestant Reformation. During the late Middle Ages, the Church and popes were increasingly caught up in secular affairs and even competed for political power against Italian princes. Furthermore, the popes began living lavishly to the point where the Church had to increase its fees in sacraments such as baptism and marriage in order to beautify churches. Not only were fees increased for services, but the selling of indulgences—this pardon lessened the time of punishment a soul faced for sins committed during an individual’s lifetime—were promoted by the clergy.

By the late 1400s, many people were buying indulgences using money or bribes to the Church. Due to this, many Catholic Christians protested and religious reverence deepened throughout Europe.

Christian humanists pressed for the Roman Catholic Church to return back to its state of simplicity; they rejected Church pomp and ceremony and highly stressed the importance of Bible study.