Karl Barth said, "The central claim of Christianity is that God has spoken." The uniqueness of this claim has lead Christians to refer to God as a Trinity. The Trinity denotes God as speaker, the Word spoken (i.e. Christ) and the interpreter of the Word (i.e. Holy Spirit). It is always better to have the author interpret his word for you when reading his works. This is how the Church understands the Holy Spirit in helping her understand God's Word.