Peter Chrysologus, like Chrysostom and other Fathers, sees the darkness in verse 19 as spiritual as well as literal; minds clouded by the grief of what they had seen on Good Friday had not yet been cleared by contact with the Risen Lord. Both fathers point out the locked doors as signifying the fear in which the Apostles still lived. The resurrected body of Christ gives us, St Augustine comments, a foretaste of our own resurrected bodies. St Gregory the Great adds that he shows us that our resurrected bodies will be incorruptible and yet real bodies
St Gregory the Great draws a parallel between Christ entering now through the closed doors, and his coming into the world through the closed doors of the Virgin’s womb. He stands before the Apostles, Gregory of Nyssa tells us, as True God. We see, St Cyril adds, by the marks of the wounds that this is indeed the same body which suffered on the Cross for us – that Temple was, as he promised, raised up after three days. As we saw from the transfiguration, the sight of his heavenly body could not be endured by sinful man, but as yet he had not ascended. In his greeting, he bestows that peace – the tranquillity of soul – which his presence always brings. It is the same Grace Paul desires for believers when he writes to the Philippians. The peace of God which passes all understanding is, in fact, the spirit of Christ, who fills those who share in him with every blessing.
After he has comforted his followers, Jesus commissions them in love. St Cyril comments that even as he was sent by the Father, so his disciples are now sent by him. Now, and only now, is their real mission revealed. They are to go to the ends of the earth calling sinners to repentance; they are to minister to all those caught in the chains of the slavery of sin. It is not their own will they must now follow, but that of Christ. As he and St Gregory the Great note, they are being sent not into the joy of the world, but to suffer, as he had suffered.
St Gregory Nazianzus notes there were three occasions on which the disciples were able to receive the Spirit: before he was glorified by the Passion; after he was glorified by the Resurrection; and on the day of Pentecost. They first of these manifested itself in the healing of the sick and the casting out of devils; the second does so as he breathes his spirit upon them here; and the third will come in the form of tongues of fire.
It is through the Spirit that love comes, St Augustine comments in his book on the Trinity. This, St Cyril of Jerusalem notes, is the second breathing of the Spirit, the first being in Genesis where it was stifled by wilful sin; this one will will enliven them and enable them to preach the Gospel to the very ends of the earth. The authority of the Apostles. St Cyprian reminds us, is found only in Christ, and in their united action, and in the unity of the Church that grew from their missionary efforts, and is traced back to their one Lord who is the bond of unity.
St Cyril of Alexandria comments that the Son, sharing the same nature as the Father, has the Spirit in the same manner that the Father would be understood to have the Spirit – this is why Jesus breathes on the disciples. It is through the Spirit, he and St Athanasius note, that Christ gives power to his followers.