What is the next part of his testimony? You will find it in the third chapter: God is only to be approached in a spiritual way. To come to God, “ye must be born again.” That which is born of flesh is flesh, and cannot commune with God, who is a spirit. That which is born of the Spirit is spirit, and can commune with the holy God, and understand spiritual things. My hearers, there is no coming to God by a priest of human consecration, no coming by outward ritual, form, and ceremony: “God is a Spirit: and they that worship him must worship him in spirit and in truth.” You must have a spiritual nature, that the Spirit of God may commune with you. Only by a spiritual nature can you have intercourse with the great Invisible. Your spirit can be in fellowship with God, the mighty Spirit; but what can you do till a spirit is created in you? This was our Lord’s testimony to Nathanael; and I suppose that, by some means, John the Baptist had heard of it; but whether he had or had not does not matter to my purpose at this time; it is certainly a part of the testimony of Jesus.
–Charles Spurgeon, “Christ’s Testimony Received”–