From the Pulpit...
Understood by No One - Matt Postiff
The natural man is a person who does not have the Spirit of God living within him or her and thus does not benefit from hearing the Word of God. Receive means "to welcome, to embrace, to make something one's own." The natural self cannot take in the things that are revealed by the Spirit. The one who is spiritual is indwelt and empowered by the Holy Spirit and can thus discern and comprehend spiritual things. The unspiritual (those who dwell in the flesh, or their sin nature) cannot judge believers regarding spiritual things, but believers can certainly sharpen their brothers and sisters in Christ.