Christ Jesus says: "“When the Spirit of Truth comes, He will guide you into all truth, for He will not speak on His own authority, but whatever He hears He will speak, and He will declare to you the things that are to come. He will glorify me, for He will take what is mine and declare it to you. All that the Father has is mine; therefore I said that He will take what is mine and declare it to you.”
Nothing is sadder than when people hear that the Spirit is the Spirit of Truth and think that this just means the Spirit is "accurate" - that He happens to be right.
He is the Spirit of Truth -- and our Lord Christ Jesus says that He Himself is the Way, the TRUTH, and the Life. The Spirit is the Spirit of Christ - Who always points to Christ, gives Christ, takes Christ's Righteousness and declares it unto you.
The Spirit always drives to Christ. If your sermons aren't driving to Christ, no matter how "true" they are, no matter how nice they are from a moral perspective or in terms of practical wisdom, if they are not giving the good things of Christ, if they do not give Christ's own life to enliven folks... they are... sad and shallow.