Thematic Bible: Why the world cannot receive nor know the spirit of God

Jesus said unto him, Have I been such a long time with you, and yet thou hast not known me, Philip? He that has seen me has seen the Father; and how sayest thou then, Show us the Father? Believest thou not that I am in the Father and the Father in me? The words that I speak unto you I speak not of myself; but the Father that dwells in me, he does the works. Believe me that I am in the Father and the Father in me, or else believe me for the very works' sake. read more.
Verily, verily, I say unto you, He that believes in me, the works that I do he shall do also; and greater works than these shall he do because I go unto my Father. And whatsoever ye shall ask the Father in my name, that will I do, that the Father may be glorified in the Son. If ye ask any thing in my name, I will do it. If ye love me, keep my commandments; and I will ask the Father, and he shall give you another Comforter, that he may abide with you for ever, even the Spirit of truth, whom the world cannot receive because it does not see him, or know him; but ye know him, for he dwells with you and shall be in you. I will not leave you orphans; I will come to you. Yet a little while, and the world shall see me no more, but ye shall see me; because I live, ye shall live also.

But the natural man does not perceive the things of the Spirit of God, for they are foolishness unto him; neither can he understand them because they are spiritually discerned. But he that is spiritual discerns all things, yet he is discerned by no one. For who has known the understanding of the Lord? Who has instructed him? But we have the understanding of Christ.