Next of course you will tell me about apostolic succession; does such a line of succession pass through murderers and bastard-makers?
It's impossible to correspond to a hate monger gnostic with unhistorical facts
I wish you well in your search.
Pope John XI (the “probable”bastard son of a Pope who became a Pope during the “reign of the harlots”)
Date of birth unknown, became pope in 931; d. 936. He was the son of Marozia by her first marriage with Alberic; some, taking Liutprand and the “Liber Pontificalis” as their authority, assert that he was the natural son of Sergius III (”Johannes, natione Romanus ex patre Sergio papa”, “Liber Pont.” ed. Duchesne, II, 243). Through the intrigues of his mother, who ruled at that time in Rome, he was raised to the Chair of Peter, and was completely under the influence of the Senatrix et Patricia of Rome. To strengthen her own power Marozia married her brother-in-law Hugh, King of Provence and Italy, whose reign in Rome was so tyrannical that a strong opposition party sprang up among the nobles under the leadership of Alberic II, the younger son of Marozia. This party succeeded in overthrowing the rule of Marozia and Hugh; Marozia was cast into prison, but her husband escaped from the city. In this way Alberic became ruler of Rome, and the pope, who suffered by his mother's fall, now became almost entirely subject to his brother, being only free in the exercise of his purely spiritual duties. All other jurisdiction was exercised through Alberic. This was not only the case in secular, but also in ecclesiastical affairs. It was at the instance of Alberic that the pallium was given to Theophylactus, Patriarch of Constantinople (935), and also to Artold, Archbishop of Reims (933). It was this pope who sat in the Chair of Peter during its deepest humiliation, but it was also he who granted many privileges to the Congregation of Cluny, which was later on so powerful an agent of Church reform.
I'm not sure it's going to be possible to have a reasoned conversation here, but I'll try,
From our POV that argument smacks of "works-righteousness". The wonder is not only that some Popes were scoundrels whom Dante, no doubt with little fear of contradiction, wrote into the Inferno. The wonder is also that such scoundrels did not turn the Church aside from her essential task and message.
If we are going to adopt "simul justus et peccator" as a standard, well, peccatores are all over the Church, and yet the Gospel is preached and souls are saved.
In other news, I think the title of this thread is needlessly inflammatory, but Catholic ecclesiology and Protestant ecclesiology (to the extent that that is one thing) differ greatly. They can't both be right. So you all think we're teaching a heretical doctrine, and we think you are. There's plenty of "nyahh, nyahh!" to go around, if that's going to be the game.