CIC 448 Very often in the Gospels people address Jesus as “Lord”. This title testifies to the respect and trust of those who approach him for help and healing.1 At the prompting of the Holy Spirit, “Lord” expresses the recognition of the divine mystery of Jesus.2 In the encounter with the risen Jesus, this title becomes adoration: “My Lord and my God!” It thus takes on a connotation of love and affection that remains proper to the Christian tradition: “It is the Lord!”3

CIC 645 By means of touch and the sharing of a meal, the risen Jesus establishes direct contact with his disciples. He invites them in this way to recognize that he is not a ghost and above all to verify that the risen body in which he appears to them is the same body that had been tortured and crucified, for it still bears the traces of his Passion.4 Yet at the same time this authentic, real body possesses the new properties of a glorious body: not limited by space and time but able to be present how and when he wills; for Christ’s humanity can no longer be confined to earth, and belongs henceforth only to the Father’s divine realm.5 For this reason too the risen Jesus enjoys the sovereign freedom of appearing as he wishes: in the guise of a gardener or in other forms familiar to his disciples, precisely to awaken their faith.6

CIC 659 “So then the Lord Jesus, after he had spoken to them, was taken up into heaven, and sat down at the right hand of God.”7 Christ’s body was glorified at the moment of his Resurrection, as proved by the new and supernatural properties it subsequently and permanently enjoys.8 But during the forty days when he eats and drinks familiarly with his disciples and teaches them about the kingdom, his glory remains veiled under the appearance of ordinary humanity.9 Jesus’ final apparition ends with the irreversible entry of his humanity into divine glory, symbolized by the cloud and by heaven, where he is seated from that time forward at God’s right hand.10 Only in a wholly exceptional and unique way would Jesus show himself to Paul “as to one untimely born”, in a last apparition that established him as an apostle.11

CIC 1166 “By a tradition handed down from the apostles which took its origin from the very day of Christ’s Resurrection, the Church celebrates the Paschal mystery every seventh day, which day is appropriately called the Lord’s Day or Sunday.”12 The day of Christ’s Resurrection is both the first day of the week, the memorial of the first day of creation, and the “eighth day,” on which Christ after his “rest” on the great sabbath inaugurates the “day that the Lord has made,” the “day that knows no evening.”13 The Lord’s Supper is its center, for there the whole community of the faithful encounters the risen Lord who invites them to his banquet:14
The Lord’s day, the day of Resurrection, the day of Christians, is our day. It is called the Lord’s day because on it the Lord rose victorious to the Father. If pagans call it the “day of the sun,” we willingly agree, for today the light of the world is raised, today is revealed the sun of justice with healing in his rays.15

1 Cf Mt 8:2; 14:30; 15:22; et al.
2 Cf. Lk 1:43; 2:11.
3 Jn 20:28,21:7.
4 Cf. Lk 24:30,39-40, 41-43; Jn 20:20, 27; 21:9,13-15.
5 Cf. Mt 28:9, 16-17; Lk 24:15, 36; Jn 20:14, 17, 19, 26; 21:4.
6 Cf. Mk 16:12; Jn 20:14-16; 21:4, 7.
7 Mk 16:19.
8 Cf Lk 24:31; Jn 20:19, 26.
9 Cf. Acts 1:3; 10:41; Mk 16:12; Lk 24:15; Jn 20:14-15; 21:4.
10 Cf. Acts 1:9; 2:33; 7:56; Lk 9:34-35; 24:51; Ex 13:22; Mk 16:19; Ps 110:1.
11 1 Cor 15:8; cf. 9:1; Gal 1:16.
12 SC 106.
13 Byzantine liturgy.
14 Cf. Jn 21:12; Lk 24:30.
15 St. Jerome, Pasch.: CCL 78, 550.