There's the physical realm of which we all live, and there's the spiritual realm where God exists. One can use their 5 senses to understand the physical realm, but it takes disciplined intellect and proper study to understand the spiritual realm. Rockhead has never demonstrated any genuine desire to understand the spiritual realm as it would require putting out effort he simply doesn't care to exert. So be it.
All mankind can come to understand the spiritual realm, so it's not a matter of Rockhead not having the capacity to do so, it's a matter of free-will if one wishes to put out the proper effort, and there's nothing to suggest he holds that desire. He's not alone in this. For many people, it's easier to dismiss something that asks you to change your life, which would mean turning over your will and your desires to something on a higher plane and a higher purpose, the spiritual being higher than the physical. To the Rockhead's of the world, their physical desires are their only higher purpose. However, his simplicity of intellect (I'm being kind) does not lessen the fact that there is a spiritual realm, it can be studied, and a sufficient understanding of it can be achieved.
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