OneAccord,
Thanks for your questions.
Acts 19 makes it very clear that when Paul first encountered them
they were disciples of John the Baptist. They were not followers of Christ yet. But after they understood that the apostle Paul was declaring that John the Baptist said the people should believe on him that should come after him, "they were baptised in the Name of the Lord Jesus" (
Acts 19:4). Thus, they went from being disciples of John the Baptist to disciples of Jesus after baptism in Jesus Name and the infilling of the Holy Ghost.
Regarding Saul being called "Brother" by Ananias, I needn't point out that they were both Israelites, Jews by nature and therefore quite literally "brothers", even before salvation.
If you're not baptised in Jesus Name and filled with the Holy Ghost speaking in tongues you ain't in the Body!
Love ya!