In the same vein as the OP, we see two stories of Christians who had not heard of Christian baptism. Ponder that. These converts to Christianity knew ONLY the OT and yet became Christians in some sense. They never read Paul's works nor the Gospels and they practiced an Essenic Jewish baptism as John had. The writer of Acts includes these early 'Christians' as immediately adopting the "more correct" Proto-Orthodox version of Christianity.
24 Now a certain Jew named Apollos, an Alexandrian by race, [a]an eloquent man, came to Ephesus; and he was mighty in the scriptures. 25 This man had been [b]instructed in the way of the Lord; and being fervent in spirit, he spake and taught accurately the things concerning Jesus, knowing only the baptism of John: 26 and he began to speak boldly in the synagogue. But when Priscilla and Aquila heard him, they took him unto them, and expounded unto him the way of God more accurately. 27 And when he was minded to pass over into Achaia, the brethren encouraged him, and wrote to the disciples to receive him: and when he was come, he [c]helped them much that had believed through grace; 28 for he powerfully confuted the Jews, [d]and that publicly, showing by the scriptures that Jesus was the Christ.
Acts has name dropped a number of famous/infamous persons as part of this program of revisionism and does so here again. Apollos, someone otherwise known only from 1 Corinthians as a kind of rival to Paul is effectively rehabilitated into the proto-Orthodoxy.
In the next chapter again in Ephesus we get another story of Christians who had been baptized as Essenes and had seemingly implausibly never heard of the 'holy spirit'.
19 And it happened that while tApollos was at Corinth, Paul passed uthrough the inland1 country and came to Ephesus. There he found some disciples. 2 And he said to them, v“Did you receive the Holy Spirit when you believed?” And they said, “No, wwe have not even heard that there is a Holy Spirit.” 3 And he said, x“Into what then were you baptized?” They said, “Into yJohn’s baptism.” 4 And Paul said, y“John baptized with the baptism of repentance, telling the people zto believe in the one who was to come after him, that is, Jesus.” 5 On hearing this, athey were baptized in2 the name of the Lord Jesus. 6 And bwhen Paul had laid his hands on them, the Holy Spirit came on them, and cthey began speaking in tongues and dprophesying. 7 There were about twelve men in all.
It's easy to conclude that Christian roots lay in Hellenized Jewish circles who had extrapolated the Christ story from OT and related texts. IMO these passages seem to preserve an early tradition consistent with this model of Christian origins while at the same time subsuming this form of Christianity into the fold of orthodoxy 80-100 years later.