The purpose of God's Holy Spirit is to reveal Truth to those who are sincere in seeking the Truth of God. These are the written words of Jesus from the Holy Bible:
But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me: (John 15:26)
On the flipside, Satan can and does use religious deception with even the counterfeit appearance of "angels" and apparitions of "Jesus" through which false prophets have started pseudo-Christian cults and false religions as those previously mentioned.
For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for Satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works. (2 Corinthians 11:13-15)
The Holy Bible is the Standard for knowing God's Truth and any and all forms of religious instruction are to be analyzed and compared with the Bible to see whether there is agreement. Where there is disagreement, the Holy Bible is the most valid and reliable Truth to base one's faith in Jesus upon.
Herein is the reliance of God's Word from The Holy Bible:
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works.(2 Timothy 3:16-17)
There Is Only One Truth
again, how do YOU KNOW that the voice YOU HEARD was not satan? you claim the voice or apparition others have seen are satan, and that they were lead down the wrong path. But how do YOU KNOW?
the bible certainly didn't say god was going to speak to you.
the book is true cuz it says it is true, that is a terrible argument to have to rely on, they all make the same claim, so it adds nothing to the debate to bring it up.