From the catechism
scborromeo.org/ccc/p1s1c2a2.htm
I. THE APOSTOLIC TRADITION
75 “Christ the Lord, in whom the entire Revelation of the most high God is summed up, commanded the apostles to preach the Gospel, which had been promised beforehand by the prophets, and which he fulfilled in his own person and promulgated with his own lips. In preaching the Gospel, they were to communicate the gifts of God to all men. This Gospel was to be the source of all saving truth and moral discipline.”
In the apostolic preaching. . .
76 In keeping with the Lord’s command, the Gospel was handed on in two ways:
- orally “by the apostles who handed on, by the spoken word of their preaching, by the example they gave, by the institutions they established, what they themselves had received - whether from the lips of Christ, from his way of life and his works, or whether they had learned it at the prompting of the Holy Spirit”;
- in writing “by those apostles and other men associated with the apostles who, under the inspiration of the same Holy Spirit, committed the message of salvation to writing”.34
. . . continued in apostolic succession
77 “In order that the full and living Gospel might always be preserved in the Church the
apostles left bishops as their successors. They gave them their own position of teaching authority.” Indeed, “the apostolic preaching, which is expressed in a special way in the inspired books, was to be preserved in a continuous line of succession until the end of time.”
IN BRIEF
96 What Christ entrusted to the apostles, they in turn handed on by their preaching and writing, under the inspiration of the Holy Spirit, to all generations, until Christ returns in glory.
As noted by another poster, Paul is the exception, the only apostle not to receive his instruction directly from Jesus.
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.” Christ’s body was glorified at the moment of his Resurrection, as proved by the new and supernatural properties it subsequently and permanently enjoys. 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. 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.
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.
IV. THE CHURCH IS APOSTOLIC
857 The Church is apostolic because she is founded on the apostles, in three ways:
- she was and remains built on “the foundation of the Apostles,”**362the witnesses chosen and sent on mission by Christ himself;363 **
The bishops - successors of the apostles
861 “
In order that the mission entrusted to them might be continued after their death, [the apostles] consigned, by will and testament, as it were, to their immediate collaborators the duty of completing and consolidating the work they had begun, urging them to tend to the whole flock, in which the Holy Spirit had appointed them to shepherd the Church of God. They accordingly designated such men and then made the ruling that likewise on their death other proven men should take over their ministry.”
862 “Just as the office which the Lord confided to Peter alone, as first of the apostles, destined to be transmitted to his successors, is a permanent one, so also endures the office, which the apostles received, of shepherding the Church, a charge destined to be exercised without interruption by the sacred order of bishops.” Hence the Church teaches that “**the bishops have by divine institution taken the place of the apostles **as pastors of the Church, in such wise that whoever listens to them is listening to Christ and whoever despises them despises Christ and him who sent Christ.”
Anyway, from the above you can see that the Church uses the term Apostle to refer to the original 11 plus St. Paul. Although the church continues to be apostolic, that is preach and teach what Jesus handed on, the bishops are not Apostles but their successors.