Darned good question!!
Pope Stephen VI (896–897), who had his predecessor Pope Formosus exhumed, tried, de-fingered, briefly reburied, and thrown in the Tiber.[1]
Pope John XII (955–964), who gave land to a mistress, murdered several people, and was killed by a man who caught him in bed with his wife.
Pope Benedict IX (1032–1044, 1045, 1047–1048), who "sold" the Papacy
Pope Boniface VIII (1294–1303), who is lampooned in Dante's Divine Comedy
Pope Urban VI (1378–1389), who complained that he did not hear enough screaming when Cardinals who had conspired against him were tortured.[2]
Pope Alexander VI (1492–1503), a Borgia, who was guilty of nepotism and whose unattended corpse swelled until it could barely fit in a coffin.[3]
Pope Leo X (1513–1521), a spendthrift member of the Medici family who once spent 1/7 of his predecessors' reserves on a single ceremony[4]
Pope Clement VII (1523–1534), also a Medici, whose power-politicking with France, Spain, and Germany got Rome sacked.
The point is: Christianity didn't just begin in the year 1500 with the Protestant Reformers, who themselves were quite tainted with scandal and sin- as their OWN theology attests to: total depravity! Right?
God knows who His people are whether in Catholic or Protestant contexts. :)