"It might be hard to understand how an argument over indulgences in 1517 could have led to Luther’s excommunication from the papal church in 1521. But between these years, the arguments over repentance, grace, and faith required that Luther challenge the authorities that his opponents were using to fight against the gospel, the pope’s decretals and canon law. Luther had no other choice but to challenge the lesser authorities that brazenly withstood the greater authority of Scripture, God’s own Word.
Challenging the Pope’s authority was all but forbidden. The memories of Jon Huss’ fate hung like a
shadow over the slightest hint of rebellion in the western church. But Luther’s conscience was pricked. He was convinced, by God the Holy Spirit himself through the Bible, that the decrees and canon law were in error. To let the Scripture have free course, therefore, the doctrines of the popes had to stand aside.
And so, in preparing for the debate, Luther added a 13th thesis to the original 12. It read,
In a letter to his friend Spalatin he wrote,
Eck described the impossibility of the Church militant upon the earth to lack a head, a leader to guide them all. He argued from various extrascriptural authorities to foment fears of ecclesial chaos if the pope lost even a smidgen of his authority.
Luther wasn’t deterred. He argued that the true head of the church on earth is Christ himself. He needs no worldly intermediary. He governs his church by his Word.
Eck seemed to have the crowd in his hand. The citizens and students at Leipzig never wavered in their support.
When the proceedings of the debate were submitted to the two sets of judges, the theologians of Paris decided in Eck’s favor and Erfurt was silent.
Luther, dejected by a seeming defeat, returned to Wittenberg knowing that things could only get worse for him. Not only had Eck pressed him on his denial of papal authority, he exposed that Luther also had to reject conciliar authority as equal with the Scriptures. The excommunication was all but certain." BrianFlamme
How many are the days of thy servant?
when wilt thou execute judgment on them that persecute me?
Psalm 119:84
Challenging the Pope’s authority was all but forbidden. The memories of Jon Huss’ fate hung like a
And so, in preparing for the debate, Luther added a 13th thesis to the original 12. It read,
“13. The very callous decrees of the Roman pontiffs which have appeared in the last four hundred years prove that the Roman church is superior to all others. Against them stand the history of eleven hundred years, the test of divine Scripture, and the decree of the Council of Nicaea, the most sacred of all councils.”
Luther didn’t make these assertions carelessly. In a letter to his friend Spalatin he wrote,
"For my debate I am examining the decretals of the Popes, and let me tell you below my breath that I am undecided whether the Pope is Antichrist or his apostle, because in these decretals – I am telling the truth! – he has miserably perverted and crucified Christ.”
Luther didn’t care about attacking the pope or any other ecclesial authority capriciously. 
Eck described the impossibility of the Church militant upon the earth to lack a head, a leader to guide them all. He argued from various extrascriptural authorities to foment fears of ecclesial chaos if the pope lost even a smidgen of his authority.
Luther wasn’t deterred. He argued that the true head of the church on earth is Christ himself. He needs no worldly intermediary. He governs his church by his Word.
Eck seemed to have the crowd in his hand. The citizens and students at Leipzig never wavered in their support.
When the proceedings of the debate were submitted to the two sets of judges, the theologians of Paris decided in Eck’s favor and Erfurt was silent.
Luther, dejected by a seeming defeat, returned to Wittenberg knowing that things could only get worse for him. Not only had Eck pressed him on his denial of papal authority, he exposed that Luther also had to reject conciliar authority as equal with the Scriptures. The excommunication was all but certain." BrianFlamme
How many are the days of thy servant?
when wilt thou execute judgment on them that persecute me?
Psalm 119:84