BIBLE READING : 1 CORINTHIANS 2:7-13
Special Verse: 1 Corinthians 2:14
But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
A natural man is one that thinks only carnally and hasn't renewed renewed his mind with the word of God. Unfortunately most Christians still live with the natural mind. That is why it is difficult for them to appreciate spiritual concepts. This is why faith looks like foolishness. Before Jesus went to the cross, all his disciples were unable to perceive his mission on earth which was that he was born to die. Recall in Matthew 16:16-17, Jesus categorically said that flesh and blood didn't reveal his divinity to Peter. Even the prophets of old didn't understand the prophecies they gave about the coming Messiah.
This makes it clear that the things of God must be revealed to man by the spirit of God. This implies that the only way one can walk in God's perfect will is by building a close relationship with the Spirit through the word of God. It isn't by joining groups in church or being part of activities in the church. Those are all religious activities by themselves not relationship. However, anytime spent seeking a knowledge of the Holy Spirit isn't wasted, it results in fellowship and an investment in ones future.