1. Shine upon us, Lord, the light of your face! (cf. Ps 4:7)

With such words the Church prays in today's liturgy. He asks for divine light. He asks for the gift of knowing the Truth. He asks for faith.

Faith is the knowledge of the Truth, which comes from the testimony of God himself.

At the centre of our faith is the resurrection of Christ, through which God Himself bore witness to the Crucified One. The testimony of the Living God confirmed in the resurrection the truth of the Gospel, which Jesus of Nazareth proclaimed. He has confirmed the truth of all his works and words. He confirmed the truth of his mission. The resurrection gave the final and most complete expression of that messianic power, which was in Jesus Christ. Truly he is the one sent by God. And divine is the word that comes from his lips.

When, today, the third Sunday of Easter, we invoke: "Let the light of your countenance shine upon us, O Lord" (cf. Ps 4:7), we ask that through Christ's resurrection, faith may be renewed in us, illuminating the paths of our lives and directing them towards the Living God.

2. At the same time, the liturgy [...] shows us how this faith was built - and continues to be built - which, being a true gift from God, has at the same time its human dimension and form.

The resurrection of Jesus of Nazareth is the main source of irradiation of this light, from which the knowledge of God's revealed Truth develops in us. The knowledge and acceptance of it as divine truth.

To form the human dimension of faith, Christ himself chose witnesses of the resurrection from among men. These witnesses were to become those who from the beginning were bound to him as disciples, from among whom he alone had chosen the Twelve and made them his apostles.

To them too Jesus of Nazareth, to them who were witnesses of his death on the cross, he appeared alive after his resurrection. He spoke to them and in various ways convinced them of the identity of his person, of the reality of his human body.

"Why are you troubled, and why do doubts arise in your heart? Look at my hands and my feet: it is indeed me! Touch me and see; a ghost has no flesh and bones as you see that I have" (Lk 24:38-39).

Thus he spoke to them when "amazed and frightened they thought they saw a ghost" (Lk 24:37).

"But because for great joy they still did not believe and were astonished, he said, 'Have you anything to eat here?' They offered him a portion of roasted fish; he took it and ate it before them" (Lk 24:41-43).

Thus the host of resurrection witnesses was formed. They were the men who personally knew Christ, heard his words, saw his works, experienced his death on the cross, and afterwards saw him alive and conversed with him as with a living person after the resurrection.

3. When these men, the apostles and disciples of the Lord, having received the Holy Spirit, began to speak publicly of Christ, when they began to proclaim him to men (first in Jerusalem) they first referred to the commonly known facts.

You "handed him over and denied him before Pilate, while he had decided to set him free" - so said Peter to the inhabitants of Jerusalem - you instead denied the Holy and Righteous One, you asked for a murderer to be pardoned" (i.e. Barabbas)! (Acts 3:13-14).

From the events surrounding Christ's death the speaker moves on to the resurrection: "...you killed the author of life. But God raised him from the dead, and of this we are witnesses" (Acts 3:15).

Peter speaks alone - but at the same time he speaks on behalf of the whole apostolic college: "we are witnesses" (Acts 3:15). And he adds: "Now brothers, I know that you acted in ignorance, as did your leaders" (Acts 3:17).

4. From the description of the events, from the testimony of the resurrection, the apostle moves on to prophetic exegesis.

To such an exegesis of death and resurrection his disciples had been prepared by Christ himself.

We have proof of this in the encounter described in today's Gospel (according to Luke). The Risen One says to the disciples: "These are the words I spoke to you while I was still with you: all things written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled" (Lk 24:44).

"... And he said: Thus it is written: Christ shall suffer and rise from the dead the third day, and in his name shall be preached to all nations repentance and forgiveness of sins, beginning from Jerusalem. Of this you are witnesses' (Lk 24:46-48).

And the evangelist adds: "Then he opened their minds to the understanding of the Scriptures" (Lk 24:45).

From Peter's speech taken from the Acts of the Apostles, which we read in today's liturgy, we see how effective this "opening of their minds" was.Peter, after presenting the events connected with the death and resurrection of Christ, continues: "But God has thus fulfilled what he had foretold by the mouth of all the prophets, that his Christ would die. Repent therefore and change your lives that your sins may be blotted out..." (Acts 3:18-20).

We find in these words of the apostle the clear echo of Christ's words: of the illumination, which the disciples experienced in their encounter with the Risen Lord.

Thus the faith of the first generation of Christ's confessors was built: of the generation of the apostles' disciples. It sprang directly from the declaration of the eyewitnesses of the Cross and Resurrection.

5. What does it mean to be a Christian?

It means: continuing to accept the testimony of the Apostles, eyewitnesses. It means: believing with the same faith, which was born in them from the works and words of the Risen Lord.

The Apostle John writes (this is the second reading of today's liturgy): "By this we know that we have known him (i.e. Christ) if we keep his commandments. He who says, "I know him" and does not keep his commandments is a liar, and the truth is not in him; but he who keeps his word, in him the love of God is truly perfect" (1 John 2: 3-5).

The Apostle speaks of living faith. Faith is alive through works that conform to it. These are the works of charity. Faith is alive through the love of God. Love is expressed in the keeping of the commandments. There can be no contradiction between knowledge ("I know him") and the actions of a confessor of Christ. Only he who completes his faith with works remains in the truth.

Thus the Apostle John addresses the recipients of his first letter with the affectionate word "little children", and invites them "not to sin" (cf. 1 John 2:1). At the same time, however, he writes: 'But if anyone has sinned, we have an advocate with the Father, Jesus Christ the righteous. He is a victim of atonement for our sins: not only for our own, but also for those of the whole world' (1Jn 2:1f).

John, apostle and evangelist, proclaims in the words of his letter, written towards the end of the first century, the same truth that Peter proclaimed shortly after the Lord's ascension. This is the truth about conversion and the remission of sins by the power of Christ's death and resurrection.

6. What does it mean to be a Christian?

Being a Christian - today in the same way as then, in the first generation of Christ's confessors - means continuing to accept the testimony of the apostles, who were eyewitnesses. It means believing with the same faith, which was born in them from the works and words of Christ, confirmed by his death and resurrection.

We, too, belonging to the present generation of confessors of Christ, must ask to have the same experience as the two disciples of Emmaus: "Lord Jesus, make us understand the Scriptures; may our hearts burn in our breasts when you speak to us" (cf. Lk 24:32).

Let the heart "burn"!: because faith cannot be just a cold calculation of the intellect. It must be vivified by love. Living through the works in which the truth revealed by God is expressed as the inner truth of man.

Then we too - even if we were not eyewitnesses of the works and words, death and resurrection - inherit from the Apostles their testimony. And we ourselves also become witnesses of Christ.

To be a Christian is also to be a witness to Christ.

7. Then also faith - living faith - is formed as a dialogue between the Living God and the living man; of this dialogue we find some expressions in the Psalm of today's liturgy: "When I call upon you, answer me, God, / my righteousness: / from anguish you have delivered me; / mercy on me, hear my prayer" (Ps 4:2). "...the Lord hears me when I call upon him. / Tremble and do not sin, / On your bed reflect and be appeased. / Offer sacrifices of righteousness / and trust in the Lord. / Many say, "Who will make us see good?"Let the light of thy countenance shine upon us, O Lord; / Thou hast put more joy in my heart / than when wine and wheat abound; / In peace I lay me down, and straightway I fall asleep: / Thou alone, O Lord, in safety make me rest" (Ps 4:4-9).

And the psalmist himself adds: "Know that the Lord does wonders for his faithful" (Ps 4:4).

[Pope John Paul II, homily to Sts. Marcellinus and Peter 25 April 1982]