I think just about everyone would say that they are receiving the Holy Spirit's teaching to qualify what they believe, (and their "interpretation" which they would say was revealed by God's Spirit).
I agree 100% that we must rely on the inspiration of God's Spirit which inspired the Word to begin with. But how do we know for sure who is receiving the true Revelation of the Spirit? How do we know for sure if we are?
The next answer might be that "the Spirit of God bears witness with our spirits" that what we believe is the Truth. Even though this is true, everyone could still say that as a qualifying of what they believe, couldn't they?...and we know they do. Of course a lot of them just believe certain things because their denomination says it's so.
I wouldn't be asking these questions if I didn't think I had the answer to the dilemma. :o)
I believe the answer lies in the fact that God has a private, intimate, one-on-one relationship with His own. He knows those that are His, and His own are "given to know Him" by Revelation of His Spirit. Matthew 16:17 & 2 Tim. 2:19 & John 17:1-3
You might say it is that "secret place of the Most High".
Many individuals and groups can be convinced in various ways as to the presumed validity of what they believe, BUT the called, chosen and elect of God ....KNOW THAT THEY KNOW THAT THEY KNOW. That may sound arrogant and presumptuous, but it is what has always gotten God's despised few (including Jesus) into trouble with the world and religious counterfeits since the beginning.
Can you imagine the confidence and persuasion which was behind John's statement in 1 John 4:5,6....?
"They are of the world: therefore speak they of the world, and the world heareth them. We are of God: he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the spirit of truth, and the spirit of error." This was not just between the world and Christians, but in the discerning of antichrist spirits in religious circles....verses 1-3.
Even in the natural we can honestly be a part of a certain family, and we KNOW that we are because we have "inside information"...so to speak. We have a direct relationship with the father of the family and he makes his will and ways known unto us. Now an outsider could come in and emmulate and intellectually try to "be one of us", but those who truly are "of the father" can discern the alien in their midst.
Malachi 3:18 "Then shall ye return, and discern between the righteous and the wicked, between him that serveth God and him that serveth him not."
It is all discerned and known by what people SPEAK. What spirit and origin is their speech of?
God reveals His Foundations and Ways to His own. The original doctrines and ordinances as they were originally given and intended to be adhered to. From the Revelation of the Name of Jesus Christ to every mystery of His Kingdom....these Revelations separate the true from the false. It started with Cain and Abel and that same difference between Revelation and one's own ideas still divides the two.
Jesus said, "if any man will do His will, he shall know of the doctrine, whether it be of God, or whether I speak of (from) myself." John 7:17
Only God's own are drawn into this KNOWING relationship of the Father's will. To the rest Jesus will say, "depart from Me; I never knew you."
There has been an allowance of the two different seeds growing together up until this imminent time of harvest. A full fledged manifestation of the two different seeds are coming to a head. God is now in the process of showing the true signs of both and a definite and, somewhat violent, separation is beginning to take place.
While the mixed multitudes are gathering together under the guise of false unity, carnality and compromise, God's elect remnant are ripening in the divine assurance of revealed Truth and true maturity. This all in preparation of the soon anticipated "manifestation of the sons of God."
God bless. I hope this edifies and enlightens.