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). We can know all that the Spirit revealed to Paul, read it, and then know all he knew. That is no small matter because the Word of God is living and more powerful than any two-edged sword (Hebrews 4:12). Are imaginary voices more powerful and meaningful than that? 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). Really listening to the written words the Spirit gave us all is "hearing what the Spirit says." In Hebrews 3:7-11, the writer quotes 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. If it is in the scriptures, that is all you need! They "completely" furnish the man of God. If someone thinks they need more, they are not a "man of God." The scriptures, given by the Holy Spirit, "completely furnish the man of God."
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). Everyone who says, "the Spirit told me" should be able to point to scriptures where the Spirit "told" it to all of us. The Spirit is not showing favoritism by giving some extra messages to some and not others. He gave us all we needed in the faith "once for all delivered to the saints" (Jude 3-4).