Good. Who does the ‘calling out’?
God does, when He saves them through faith on the Word as it is preached, and they are assembled into a local church.
For instance, everywhere Paul the Apostle went preaching, people were saved, and then gathered together into local churches, which is why we see the churchES of Galatia, etc. spoken of.
That's the point, too - authority is conferred by God's Word, through faithfulness to it. There is no such thing as "apostolic" authority. The notion that the pastors of local churches had authority because they were installed by apostles, or by the descendants of apostles, is completely foreign to the Scripture. Any pastor of a local assembly has the same authority as Peter himself had - indeed, James the brother of Jesus, who was not an apostle, had the final word OVER Peter and the other apostles in the question before the church at Jerusalem in Acts 15 - this being the case because James was by this time the pastor at Jerusalem, not Peter.