And it is the Spirit who testifies, because the Spirit is the truth. For there are three that testify: the Spirit, the water and the blood; and the three are in agreement. —1 John 5:6-8
How does God speak? Primarily through His Word, the Bible. As far as I know how, I only preach what the Scriptures ask me to preach. I don't make up things or come up with ideas; I just follow the Bible and let it speak for itself. It means that when I speak the Holy Spirit can use my words, and thus they are not merely my words. At some stage, you become conscious that God Himself is speaking.
Sometimes God will speak in a particular context. You may be in a situation where you are suffering. Perhaps something traumatic has happened to you. Maybe you have gone through a particular kind of trial, and you happen to be in the service, and, lo and behold, the word that is spoken is so relevant and so intimate that it's almost embarrassing. You think that the preacher knows all about you, but it's only the Holy Spirit applying the Word.
In other words, once we hear God speak, it's as if we suddenly understand it. The person who hears the same old gospel week after week may say, "I have heard it before, and I know all of that." Then suddenly the truth hits him, and he says, "Oh, I see it! I see that Jesus lived on this earth, kept the law for us, and because He did, He is our righteousness. I am actually saved by what someone else did. Jesus died on the cross as my substitute, and God punished Him instead of me. The blood He shed satisfied God's justice."
"You've got it. Well, you've heard it a thousand times."
"Yes, but tonight I heard it for the first time."
Someone has said that no one has the right to hear the gospel twice until all have heard it once, which is a fine statement. But a truer statement would be that nobody hears the gospel once until they have heard it twice, and suddenly they realize that God is speaking to them. You see, only the Holy Spirit can make you understand the gospel.
Excerpted from All's Well That Ends Well (Authentic Media, 2005).