The voice of God is frightening because it spoke the world into existence.
It scares the Hebrews near Mt Sinai and Peter James and John on the MT of Transfiguration.
Without understanding the power of the word and the voice of God, you leave people thinking they must contribute something to their salvation, a diminished view of the sacraments, and weakened trust.

So much fuss about scientifically proving this or that.