The Sermon delivered by our Savior on the Mount was preceded by two significant meetings, one with His secret disciple, Nicodemus (John 3:1-21), and the other with the Samaritan Woman (John 4:4-42). In His conversation with Nicodemus, Christ spoke of being born again, born of the Spirit of God, and in Samaria He taught of God as Spirit and of the worship of the Father in spirit and truth.
Nicodemus had not known of spiritual birth before his meeting with the Lord. What interested him was the same question that troubled many other men: was this Teacher and Miracle-Worker an ordinary prophet, or was He the Christ, the promised Messiah? His desire to find the answer to this question is evident in the words with which he addressed Christ: Rabbi, we know that You are a teacher come from God; for no one can do these signs that you do, unless God is with him (John 3:2).
Aware of Nicodemus' inner state and aware of his spiritual blindness and fundamental unreadiness to receive the Truth, our Lord spoke to him of the necessity of spiritual birth: Truly, truly, I say to you, unless one is born anew, he cannot see the Kingdom of God (John 3:3). Nicodemus misunderstood these words and took them to mean a second birth from the womb. Christ, in His mercy, was patient with Nicodemus and explained to him: Truly, truly, I say to you, unless one is born of water and the spirit, he cannot enter the Kingdom of God. That which is born of the flesh is flesh, and that which is born of the spirit is spirit (John 3:5-6).
According to St. John Chrysostom, what is meant here is not birth in fact, but birth in dignity and grace. Birth in dignity is the spiritual rebirth of the man who strives constantly for the spiritual, heavenly and eternal; for man, as the Image of God, is called to live continuously with God and in God. Birth through grace is the part played by the Holy Spirit's grace in man's birth, in his regeneration justification and sanctification.
All of this was difficult for Nicodemus to understand, for in the last words spoken by the Savior, he saw a fresh mystery, and that is why he asked: How can this be (John 3:9)? Jesus explained that He was teaching not of worldly, but of heavenly things, that He was the Christ, the Son of God come down from Heaven, and that as Moses lifted up the serpent in the wilderness, so must the Son of man be lifted up, that whoever believes in Him may have eternal life (John 3:14-15).
Our salvation contains many hidden mysteries and ineffable spiritual blessings linked with them. The greatest and most fundamental mystery, along with the greatest blessing, lies in the fact that God so loved the world that He gave His only Son, that whoever believes in Him should not perish but have eternal life (John 3:16). Man should respond to this saving love of God first and foremost with faith in it and in Christ, as the Son of God and the Savior of mankind, Who came, not to judge, but to save those who believed in Him, Who came as the Light to illumine those who were in darkness and sought God's Truth, so that they should live and find salvation through it.
St. John the Evangelist, speaking of the Logos the Word of God and of those who did not accept Him, wrote: To all who received Him, who believed in His name, He gave power to become children of God; who were born, not of blood nor of the will of the flesh nor of the will of man, but of God (John 1:12-13). In these words the Evangelist points out two unfathomable mysteries, that of birth from God and that of the power to become the sons of God.
Children inherit from their parents their nature and their attributes. And what do God's spiritual sons inherit from Him? First and foremost they inherit such attributes of God's grace as love, holiness, goodness, light, kindness, peace, truth, righteousness and purity. The gifts of God are received through the Sacraments of Baptism and Chrismation and they develop and grow throughout the Christian's life.
In our Lord's conversation with the Samaritan Woman by Jacob's Well, He revealed to her the truth of the living water, welling up to eternal life (John 4:14). Then, speaking of the worship of God, He said that the true worshipers will worship the Father in spirit and truth, [because] God is spirit, and those who worship Him must worship in spirit and truth (John 4:23-24). Here, when He states that God is Spirit, Jesus is saying, according to St. John Chrysostom, that God is incorporeal and that for this reason those who worship Him must worship in spirit and truth.
And what does worshiping in Truth mean? According to St. John Chrysostom: Earlier rites, like circumcision, burnt offerings, sacrifices and the burning of incense, were merely symbols, whereas new Truth has come. Now it is not flesh that we must circumcise, but evil thoughts; now we must crucify ourselves, and exterminate and mortify our unreasonable desires. It is this that is meant by worshiping in truth. But only one who is born in the spirit can worship in this way.
The Savior's conversations with Nicodemus and with the Samaritan Woman revealed His teaching about God as Spirit and about the spiritual worship of God by those who believe. In this way He established the concepts of spirituality, of spiritual feeling, the spiritual man as compared with the non-spiritual, the natural man, the man of this world, and the man of the flesh. Thus our Lord's summons to beatitude (or blessedness) is addressed to the man who has passed through or who is passing through the process of spiritual birth, and who already partakes in the effects of the summoning and illumining grace of God, leading to faith in Christ, the Son of God and the Savior of the World. Therefore, in the Beatitudes (Matt. 5:1-12), which are sung at the Divine Liturgy, are to be found the basis for Christian Morals.