Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come. (John 16:13)
Many people are under the mistaken impression that either all truth becomes evident immediately when the Holy Ghost is received or that somehow the Holy Ghost will always speak and tell or reveal things they need to know. Both of these belief systems are appealing, but dangerously misleading. They each fail to recognize that the Holy Ghost leads us to truth; it doesn’t always just tell us. There’s a leading and guiding involved, but we have to accept it, no matter whether truth comes from a person God sends our way, the Word of God revealing truth to us, or some other means.
Let’s put on our thinking caps for a bit and look at this logically. If the Spirit of God just revealed everything to us that we need to know to please God and walk with Him, why in the world do we need the epistles? The epistles make up 21 of the 27 books of the New Testament. These are letters written to saved people to tell them how to live and act in order to please God, take care of the body of Christ (the church), and endure in the world. Why exactly would these folks need this if the Holy Ghost just revealed all truth to everyone who received it? Answer, the Holy Ghost guides people to truth. When Paul, or Peter, or John wrote to a church and said “do this” or “don’t do that”, the Holy Ghost inside those people was saying, “There, I put you into contact with them so they could tell you what you’re supposed to do to be pleasing to God.”
Now before any righteous indignation flames up, let me say that the Holy Ghost does sometimes completely reveal truth to people. I know people who knew certain things were displeasing to God long before they read it in scripture, and I’m not talking rape and murder here, I’m referring to things that most people don’t even realize displease God. How is that possible? Because the Holy Ghost can speak to us and reveal things to us, but generally, it guides us into truth rather than openly reveals truth.