The unique historical narratives in Acts can not be taken as being didactic.
Time to discuss Acts. Luke-Acts defined evangelism as prophetic utterance. Two scholarly books on this are:
(1). The Prophethood of all Believers, by Roger Stronstad.
(2). Mighty in Word and Deed: The Role of the Holy Spirit in Luke-Acts, by James Shelton.
Below I'll mix their arguments with my own. (Obviously I can't cover all the arguments found in the two books).
(1) An evangelist needs to know with 100% certainty where to preach, when to preach, and what to preach, because too many souls are at stake for inferior evangelism. 100 billion people have existed to date.
(2) Self-evidently, evangelism is most effective when 100% certainty is transmitted to the audience.
(3) Jesus promised His apostles an outpouring of power for WITNESSING (Acts 1:8). Since the Holy Spirit was helping them to talk, isn't that prophecy? Certainly. Thus for example, “it is not ye that speak, but the Spirit of your Father which speaketh in you” (Mat 10:20).
(4) The gospels including Luke-Acts were written after the OT tradition - which emphasized prophets.
(5) The first evangelist introduced in the gospels was the PROPHET John the Baptist understood to succeed the PROPHET Elijah (Lk 1:17).
(6) The expression "filled with the Spirit" is exclusive to Luke-Acts, about 14 times, save one mention by Paul. These fillings usually issued speeches reminiscient of the Spirit of prophecy falling upon OT saints. Also sundry outpourings in Luke-Acts, even when the word 'filled' isn't present, issue speeches, after the OT paradigm.
(7) Throughout the OT, marching out into battle without a clear sign from heaven (a sign presumably conferring 100% certainty) was foolish. Naturally, then, the saints in Acts defer evangelism, waiting in prayer until convincing signs appear (earthquakes, tongues of fire, mighty rushing wind, angels, dreams, visions, etc).
(8) With so many souls at stake, it was imperative for Acts to lay down, at the very outset of the book, the best possible strategy for evangelism. The strategy seen from Pentecost onward is simple: Prayer outpours a prophetic anointing for evangelism. Luke is the ONLY writer to record Christ's promise, "How much more will your heavenly Father give the Holy Spirit to them that ask him" (Lk 11:13). He was the ONLY writer to tie Christ's own prophetic anointing to prayer (Lk 3:21). In fact Luke has more verses on prayer than any NT writer. Moreover Pentecost was NOT the "gift of tongues" (as there was no interpreter) but rather PROPHECY, thus revealing prophecy's supernatural ability to overcome language barriers. After all, Peter deemed Pentecost a fullfilment of Joel's promised last-days prophetic anointings.
(9) Joel's promise says not, "They MIGHT prophesy" but rather "They SHALL prophesy". Any Christian who hasn't prophesied, therefore, has yet to partake of the evangelistic anointing of Acts. Promised land isn't always automatic. Typically one must go up and appropriate it. Thus even though Joel's promise is AVAILABLE to all believers (Acts 2:39), it is incumbent on them to obtain the Spirit of prophecy (via prayer).
(10) Forms of the word 'witness' appear some 120 times in the NT and parallel English usage. A witness in court, for example, is someone who has seen and heard a reality IN SUFFICIENT PROXIMITY AND CLARITY to accurately and reliably testify about it. Seen and heard what? Christ!!! "Ye shall be MY witnesses" (Acts 1:8).If the risen Christ has never appeared to a person face to face, he or she is not a witness of Christ, nor a witness of His resurrection. Thus Acts refers to the PROPHETS as witnesses (Acts 10:43). Two decisive passages define Paul's ongoing ministry as a witness in terms of him relaying to others things seen and heard from Christ. Thus God’s plan was that Paul visibly “see that Just One, and shouldest hear the voice of his mouth. For thou shalt be his witness unto all men of what thou hast seen and heard” (22:14-15). And again, “I have appeared [visibly and audibly] unto thee [Paul] for this purpose, to make thee a minister and a witness both of these things which thou hast seen, and of those things in which I will [later] appear unto thee” (26:16). Verses alluding to being witnesses of Christ's resurrection include Lk 1:2; Acts 1:22; 2:32; 3:15; 4:33; 5:32; 10:39, 40-41; 13:31; 14:3; 23:11. Christ could very well have limited Himself to the term 'evangelist'. Instead He added the term 'witness'. Was He trying to mislead us? Is He an incompetent instructor? Or did He mean it literally? Clearly, He meant it literally. In both testaments, prophets saw Christ face to face. And since a prophet is the ideal evangelist, it only made sense for Him to characterize such an evangelist as a witness. "The testimony (witness in the Greek)of Jesus is the Spirit of prophecy" (Rev 19:10).