The Spirit Speaks
The Spirit speaks completely through the scriptures. The Spirit gave the scriptures so that we would know what the apostles knew (Ephesians 3:3-5). When John wrote to the seven churches, it was through John's letters that those churches could "hear what the Spirit says" (Revelation 2-3). In Hebrews 3:7-11, the writer quotes from Psalms 95:7-11 and prefaces that quote with "as the Holy Spirit says." In other words, quoting from the scriptures is telling what the Spirit says. Listening to the scriptures is hearing what the Spirit says. Having no scriptures in your heart means that there is no voice of the Holy Spirit in you. The scriptures are the voice of the Holy Spirit.
The man of God is "completely" furnished by the Scriptures (II Timothy 3:16-17). The Spirit "completely" furnishes the man of God through the scriptures that the Spirit revealed. If it does not come from the scriptures, it does not come from the Spirit.
People often use their imagination apart from the scriptures, and then deceive themselves into thinking that they are being guided by the Holy Spirit. No! The scriptures are the "complete" voice of the Holy Spirit. Are you listening to the Spirit, or voices of imagination? There is safety in staying with the scriptures. All kinds of weird things are attributed to the Spirit by wild imaginations. Imaginations are not the Spirit speaking to you. The scriptures are. Find out what is so by searching the scriptures, which is what the Spirit says (Acts 17:11).