God created man a spirit being and gave him a body to be the home of his spirit. Through his physical body man was to contact the outward world which was to be his home. The knowledge of this world was to come to him through the medium of his five senses. The purpose of the nervous system was never to reveal God to man; man was to know God through his spirit.
When man died spiritually, that is, became alienated from God, he was left without a channel through which he could know God. It then became necessary for God to meet man on the level of the medium through which he gained his knowledge and that revelation is known to us as the Bible.