The "Believers" in Acts 19:1-6

I would agree with that. One is not saved under New Covenant conditions if they Have not received the Gospel (as it was revealed at Pentecost, which follows John's Ministry) and are not Baptized with the Holy Spirit (which is when one is indwelt).

They were saved at this time.

However, that does not mean they were not believers according to the revelation provided to men under Old Testament Economies. They were believers, but so was Abel, Noah, Abraham, Moses, and David. But not one of them could receive remission of sins through Christ until they received the Gospel.

And in regards to their discipleship, they were disciples of John. And John himself, though he prophesied about the Lamb of God taking away the sins of the world, was himself unaware of Christ's Ministry concerning salvation from sin:


Matthew 11

King James Version (KJV)

1 And it came to pass, when Jesus had made an end of commanding his twelve disciples, he departed thence to teach and to preach in their cities.

2 Now when John had heard in the prison the works of Christ, he sent two of his disciples,

3 And said unto him, Art thou he that should come, or do we look for another?

That is true, they were Baptized with the Holy Spirit, then baptized with water (which is an assumption, not in the text, but seeing Paul's teaching on it we can probably safely assume they were water baptized according to the usual command). If you include John's baptism, which had nothing to do with conversion, but repentance under the Law, then that would make three.

John makes it clear that the Baptism that was coming differed from his:



Matthew 3:11-12

King James Version (KJV)

11 I indeed baptize you with water unto repentance. but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:

12 Whose fan is in his hand, and he will throughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.



As did Christ:


Acts 1

King James Version (KJV)


4 And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me.

5 For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.


As does Paul in our current text:


Acts 19

King James Version (KJV)

4 Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus.




God bless.

 

beleiev that they were of a special case for the transistion period between the Covenants in Acts, as now all who believe on jesus receive Holy Spirit right then and there!