In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came to be through him, and without him nothing came to be. What came to be through him was life,
and this life was the light of the human race; the light shines in the darkness, and the darkness has not overcome it. A man named John was sent from God. He came for testimony, to testify to the light, so that all might believe through him. He was not the light, but came to testify to the light. The true light, which enlightens everyone, was coming into the world. He was in the world, and the world came to be through him, but the world did not know him. He came to what was his own, but his own people did not accept him.
But to those who did accept him he gave power to become children of God, to those who believe in his name,
who were born not by natural generation nor by human choice nor by a man’s decision but of God. And the Word became flesh and made his dwelling among us, and we saw his glory, the glory as of the Father’s only Son, full of grace and truth. John testified to him and cried out, saying, “This was he of whom I said, ‘The one who is coming after me ranks ahead of me because he existed before me.’” From his fullness we have all received, grace in place of grace, because while the law was given through Moses, grace and truth came through Jesus Christ. No one has ever seen God. The only Son, God, who is at the Father’s side, has revealed him. [Jn 1:1-18]
These verses act as a prologue to the whole Gospel, and are a hymn in praise of Jesus Christ.
As a prologue, they mention the key themes that will be developed over the course of the narrative: Jesus is the Logos, the eternal word of God (as the word, he expresses God’s thought), who, on being sent into the world, communicates, through his words and works, the truth about God and about himself, and gives mankind divine life, eternal life.
Prior to his coming, man was able to see God only indirectly: he could know God only through things and events, through reflections of his greatness. But now that the fullness of time has come, God is revealed through the human nature of Jesus Christ, who is the visible image of the invisible God (cf. Col 1:15); there can be no greater revelation of God to the world.
In fact, Jesus himself assure us: “He who has seen me has seen the Father” (14:9). “The most intimate truth which this revelation gives us about God and the salvation of man shines forth in Christ, who is himself both the mediator and the sum total of Revelation” (Vatican II, Dei Verbum, 2).
The prologue also mentions those who have been witnesses to Jesus’ life on earth – John the Baptist, and many others, disciples who believed in Jesus, and those people who rejected him.
Saint Augustine comments: “But it may be that the dull hearts of some cannot yet receive this light. Their sins weigh them down, and they cannot discern it. Let them not think, however, that, because they cannot discern it, therefore it is not present with them. For they themselves, because of their sins, are darkness. Just as if you place a blind person in the sunshine, although the sun is present to him, yet he is absent from the sun” (In Ioannis Evangelium, 1, 19).
As a hymn to Jesus Christ, these verses proclaim the divinity and eternity of the word, his role in creation, the fact that he enlightens the soul of man, his coming into the world and being rejected by it, the gifts he brings to those who believe in him.
Even though he shared our human condition, his divine glory shone out, and he (as only he could) has made known to us the saving mercy of God.
To summarize: the Gospel proclaims (as Saint Paul does elsewhere: see Col 1:15-20; Phil 2:5-11) who Jesus Christ really is, where he comes from, how he came into the world and what he has done for mankind.
To this end it portrays Jesus in a way similar to that in which wisdom is personified in the Old Testament – as eternal, and active in creation and in the instruction of man (see Prov 8:22-31; Sir 24:1-22; Wis 7:22). It also tells us something about the role of the word of God in the creation of the world (cf. Gen 1:1).
Verse 14, in a very condensed way, introduces the mystery of the incarnation. The Greek verb used by Saint John and translated in the RSV as “dwelt” etymologically means “pitched his tent,” that is, settled down to stay in a particular place.
It calls to mind the tabernacle or tent from the time of the Exodus, where God manifested his presence in the midst of the people of Israel by means of signs of his glory such as the cloud that settled over the tent (see e.g. Ex 25:8; 40:34-35).
The Old Testament also proclaims that God, and particularly his wisdom, chose a place to dwell among the people (cf. e.g. Sir 24:8; Jer 7:3; Ezek 43:9). The Son of God’s coming to live among men also fulfills the promise in Isaiah of the Immanuel or “God with us” (Is 7:14; cf. Mt 1:23).
So reading these verses of the Gospel or saying the Angelus is a valuable opportunity to make a deep act of faith and thanksgiving, and to adore the Holy human nature of the Lord, who, by becoming man, gives us the possibility of becoming children of God: “The Son of God became man,” Saint Athanasius explains, “in order that the sons of men, the sons of Adam, might become sons of God. […] He is the Son of God by nature; we, by grace” (De Incarnatione contra Apollinarium, 8).
And John Paul II teaches: “Christ’s union with man is power and the source of power, as Saint John stated so incisively in the prologue of his Gospel: ‘[The Word] gave power to become children of God.’ Man is transformed inwardly by this power as the source of a new life that does not disappear and pass away but lasts to eternal life (cf. Jn 4:124)” (Redemptor hominis, 18). The divine filiation that we acquire by union with Christ through Baptism enables us to share God’s own life in a real, supernatural way (cf. 2 Pet 1:4); it draws us into the inner life of the Blessed Trinity.
The words “grace” and “truth” are, in this context, synonymous with “steadfast love and faithfulness,” two attributes that the Old Testament constantly applies to God (see e.g. Ex 34:6; Ps 117 and 136; Hos 2:16-22).
Grace upon grace” or “grace for grace” (v. 16) means the replacement of the salvific economy of the Old Testament by the new economy of grace brought by Christ. It may also refer to the superabundance of gifts given by Jesus – grace piled on grace, all of it flowing from Christ, who has fullness of grace and therefore is an inexhaustible source of it.