You may object at this point that St. Timothy was not an apostle. I will concede that he was not an “Apostle,” with a capital “A,” but you must concede that Scripture clearly calls St. Timothy an apostle, thereby attesting to his apostolic authority:“Paul, Silvanus [Silas], and Timothy, To the church of the Thessalonians… nor did we seek glory from men, whether from you or from others, though we might have made demands as apostles of Christ.” (1 Thess. 1:1, 2:6) It is not only St. Timothy who is called an apostle by Sacred Scripture, but also St. Barnabus, Apollos, and St. Titus:St. Barnabus"But when the apostles Barnabas and Paul heard of it, they tore their garments and rushed out among the multitude…" (Acts 14:14) Apollos"I planted, Apollos watered… He who plants and he who waters are equal." (1 Cor. 3:6, 8) “I have applied all this to myself and Apollos for your benefit, brethren… For I think that God has exhibited us apostles as last of all, like men sentenced to death.” (1 Cor. 4:6,9) The objection will be raised: Titus is nowhere in Scripture explicitly called an apostle. I reply, it is implicit in what kind of authority is accorded to the apostles. Scripture testifies that only apostles are given full authority. Compare what is said of St. Paul and St. Timothy (both of whom are called “apostles”) with what is said of St. Titus:St. Paul"…nor did we seek glory from men, whether from you or from others, though we might have made demands as apostles of Christ." (1 Thess. 2:6) St. Timothy"As I urged you when I was going to Macedonia, remain at Ephesus that you may charge certain persons not to teach any different doctrine…" (1 Tim. 1:3) “Command and teach these things.” (1 Tim. 4:11) “Remind them of this, and charge them before the Lord to avoid disputing about words, which does no good, but only ruins the hearers.” (2 Tim. 2:14) St. Titus"This is why I left you in Crete, that you might amend what was defective, and appoint elders in every town as I directed you." (Tit.1:5) “Declare these things; exhort and reprove with all authority. Let no one disregard you.” (Tit. 2:15) “…our boasting before Titus has proved true. And his heart goes out all the more to you, as he remembers the obedience of you all, and the fear and trembling with which you received him.” (2 Cor. 7:14-15) …
There can be no other reason why St. Paul would leave his two spiritual “sons” (Ss. Titus and Timothy) explicit instructions about the qualifications for overseers, elders, bishops, etc. (c.f. 1 Tim 3:1-7, Tit. 1:5-9), than that he expects them to confer apostolic authority on new men who meet those requirements.