'Acquainted' in the Bible

But Peter remained standing outside the door, till the disciple who was acquainted with the High Priest came out and induced the portress to let Peter in.

"The Jews," he replied, "have agreed to request you to bring Paul down to the Sanhedrin to-morrow for the purpose of making yourself more accurately acquainted with the case.

Brethren, do you not know--for I am writing to people acquainted with the Law--that it is during our lifetime that we are subject to the Law?

For, among human beings, who knows a man's inner thoughts except the man's own spirit within him? In the same way, also, only God's Spirit is acquainted with God's inner thoughts.

By people who live on milk I mean those who are imperfectly acquainted with the teaching concerning righteousness.