Actually, there probably were 2nd and 3rd Baptist churches. Now think this through carefully and objectively. Here is what happened:The First Baptist Church of Jerusalem? Good grief, that's stretching things quite a bit isn't it? But hey, what about the 2nd and 3rd Baptist churches of Jerusalem who split from the 1st over doctrinal differences?
Like I pointed out earlier, the Baptist faith tradition is an offshoot of the Puritan-Separatist movement, which itself was an offshoot of the Anglican Church, which itself left the Latin Rite Church led by the Bishop based in Rome.
Acts 2:41 Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls.
--The 3,000 were added to a church already in existence. They were added unto "them". Who were they?
Acts 1:13 And when they were come in, they went up into an upper room, where abode both Peter, and James, and John, and Andrew, Philip, and Thomas, Bartholomew, and Matthew, James the son of Alphaeus, and Simon Zelotes, and Judas the brother of James.
14 These all continued with one accord in prayer and supplication, with the women, and Mary the mother of Jesus, and with his brethren.
15 And in those days Peter stood up in the midst of the disciples, and said, (the number of names together were about an hundred and twenty,)
--They were added to this assembly of 120 disciples that had been praying in the upper room. Mary was there, but it is the last time we hear of Mary and she was just one of the crowd with no exalted position whatsoever.
From these 3,000 we read:
Acts 2:47 Praising God, and having favour with all the people. And the Lord added to the church daily such as should be saved.
--The Lord added daily to this one church. There was no other. It grew rapidly.
Where was it meeting. That "upper room" where they were praying was on the Temple grounds.
Verse 46 also says:
Acts 2:46 And they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart,
--This would not last. The Temple was controlled by the Sanhedrin, the very ones that crucified Christ. And as they crucified Christ a great persecution would very soon rise against these Christians. Part of it would be led by Saul himself.
They would be scattered. In other places they would go first to synagogues but then be kicked out of there. From there they would meet in fields, houses, even cemeteries (the famed catacombs for example).
By Acts 15 the church in Jerusalem had grown so rapidly that historians say that it numbered between 100,000 and 300,000. But where did they meet?
What happened when Peter was imprisoned in Acts 12 after James was beheaded. Herod was going to do the same, but intercession was made for Peter by the church.
Acts 12:5 Peter therefore was kept in prison: but prayer was made without ceasing of the church unto God for him.
--If you are acquainted with the story there were a number of miraculous occurrences whereby an angel came and led Peter out of prison. Then Peter found "the place of the church" that was praying for him.
Acts 12:12 And when he had considered the thing, he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying.
Perhaps this is the Second Baptist Church of Jerusalem. They were gathered at the house of John Mark's mother, Mary, praying, as it says in verse 5--the church. The local church in Jerusalem.
Under persecution they met wherever they could.