I already told you that the horrible actions of sinful men - even if they do these acts under the impression that they are fighting FOR God - does not justify them nor, however, does it necessarily disprove the faith they say they are following. We know radical Muslims do things that are horrific and many other Muslims disapprove of their actions insisting that Islam is a "religion of peace". Can we look at their scriptures and determine which side is correct?
I can completely disapprove of the actions the Roman Catholic Church took during the Inquisitions and other persecutions they did under the false assumption that they were defending the faith against heretics. Even some Protestants did some of the same things and they were BOTH wrong. The truth of the gospel doesn't need the force of the sword of men to be preserved as God is a rewarder of those who diligently seek Him. Man will NEVER be able to fight against God - His will and purpose will not be thwarted.
The Holy Spirit testifies of truth and can teach, true. But, who are you to say you don't need a prophet? God sends His servants and you reject them outright because you have your Bible? The scriptures only get you so far. It's the servants of God that have the authority to act in His name. The Lord didn't send a herd of Bibles in to try to recover Jerusalem. He sent prophets.
It seems that your definition of a "prophet" is different than mine. The Prophets God used to reveal the truth to mankind were hand selected and His words were relayed through them. Often, the people rejected them, persecuted them and killed them, and they answered to God for their actions. These "holy men of God" spoke as they were carried along by the Holy Spirit and EVERY word they spoke was directly from God. However, there came a time where there were no longer prophets in the land. We read in Lamentations, Zechariah, 2 Chronicles and other books that God removed His prophets from among the people because of their disobedience. There weren't anymore until Christ came to earth and God again breathed His word to selected people who, in turn, wrote down God's truth - just as they did in the time before Christ - which was copied and disbursed throughout the local churches.
If, instead of prophets, who specifically received divine revelation and communicated God's word to His people, you are speaking of those people who God has given the gift of "prophecy", then we are speaking of two different kinds of prophets. There were indeed believers in the churches who God used to speak forth the truth on what God had ALREADY revealed. They expounded upon and taught the believers to grow in grace, in their faith and in their knowledge of the truth. They did not reveal new truths or come up with novel interpretations of God's truth. They were led by the Holy Spirit - and their disciples also - to teach what God desired all Christians to know. One things that separated them from the numerous false prophets that existed even back then was the Holy Scriptures. They remained the authority by which all truth claims were, and are, to be measured.
These people the Lord is referring to, call Him Lord. They are believers and He casts them out at the judgement. Notice it doesn't say anything about a Bible or scriptures as the reason they will be cast out. The cause of their weeping and gnashing of teeth is seeing all the prophets. The ones they rejected.
Why presume they are "believers"? Jesus, when speaking about those false prophets who would come and to try and deceive His sheep, said:
Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves. By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? Likewise, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus, by their fruit you will recognize them.
“Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven. Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?’ Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers!
If you notice, He says He NEVER knew them. Not that they were once His sheep but they strayed, but they were NEVER His sheep. We enter through the narrow gate - which is faith in Jesus Christ as Savior. The gate is NOT going to be Joseph Smith, Jr., or Mohammad, a Pope, Krishna, Buddha, or any prophet.
A false doctrine is a false doctrine. A couple centuries ago people were being slaughtered by the tens of thousands, tortured to death, over infant baptism. The only reason they stopped killing each other was because genocide became unpopular.
You're throwing your own "lent balls" now? The way we can know false doctrines or false prophets is by comparing them to God's holy word. It is our touchstone, our authority and rule of faith.