Matt,
Here I continue the way of proving and Onus Probandi.
1. Case of Jesus
Jews brought the false witnesses and they said Jesus said " I am able to destroy the temple of God, and to build it in three days"
Another witness say "we found this fellow perverting the nation, and forbidding to give tribute to Caesar (Luke 23:2)
What if we didn't have the New Testament but had only the witnesses by the High Priest and his fellow witnesses? Could we judge fairly about Jesus?
2. Case of Nestorius.
Nestorius was condemned as Heretic, denying Theotokos. RC often claimed that he insisted 2 persons lived in Jesus Christ. Now the documents discovered in 1895 reveals quite differently from what was thought to be Nestorian belief.
Look at this:
http://moses.creighton.edu/okeefe/THL531/projects02/Christolgy5thC/Introduction_files/Nestorius.htm
http://mb-soft.com/believe/txc/nestoria.htm
3. Conclusion
One can hardly evaluate and judge someone or some groups belief without their own writings.
If Albigenes were so harmful that they had to be masacred and killed, and their properties had to be confiscated, then there must have been any literatures or writings. Why didn't RC preserve them and reveal their own writings?
It is absolutely because Albi was right but RC was heretic! Therefore they didn't want to reveal the truth.
This is why Gamaliel prohibited the people from punishing or killing the disciples and said
" But if it be of God,ye cannot overthrow it; lest haply ye be found even to fight against God" ( Acts 5:39)
God doesn't force any one believe His truth.
Jesus prohibited Swearing, but you notice RC was forcing the people swear.
If anyone committed any civil offense such as murder or adultery, then they deserve the punishment. Otherwise, they should have been left free. RC was not confident with their own belief and teachings for themselves because they knew that they themselves were wicked and tricky, forging the false theories, full of Idolatry, disobeying the Words of God.
If they were faithful with the Words of God, they would have not killed so many Albi's.