Tell me, since you don't believe my verses from Jeremiah of the "false prophets who lead people astray with their reckless boasting" are sufficient, how do you determine who is speaking the truth and who isn't? What criteria do you use? Based upon some council of men who tell you they have the Spirit of God?
This verse from Moses does not teach that "if it isn't clear from scripture then a person can't lay claim to the issue". Otherwise Joshua could never have written the book of Joshua. The fact that other writers added to Scripture after Moses shows that the verse does not mean that "if it isn't clear from scripture then a person can't lay claim to the issue". The existence of human authorities (e.g. Moses) is fully compatible with simultaneous injunctions not to add to or subtract from the Scriptures. That is because this injunction means that the Scriptures *themselves* should not be altered without divine authorization. The injunction does not mean that there cannot also simultaneously be true and authoritative Tradition, or that there cannot also simultaneously be divinely appointed and ordained human religious authorities.
Tell me, ... how do you determine who is speaking the truth and who isn't?
We look to the sacred Magisterium, as it has spoken throughout the history of the Church and as it now speaks.
What criteria do you use?
The criterion is agreement with the sacred Magisterium.
Based upon some council of men who tell you they have the Spirit of God?
Any group of men could *claim* to have the Spirit of God. The Apostles and early Church fathers taught that the gift of ordination was received by an act of the Holy Spirit through the laying on of the Apostles hands. Only those who have received this gift can give this gift. That is why only bishops who can trace their orders back to the Apostles, and who are in communion with the bishop of Rome (who received in addition to epispocal orders Peter's keys), make up the living Magisterium.
-A8