How does one know the Holy Spirit is in a meeting?

ANSWER:  He (the Holy Spirit) CONVICTS of sin, righteousness and judgment.  John 16:8.

Derek Prince: “These are the three eternal realities in which all religion is based: sin, righteousness and judgmentThere will be sin, there will be righteousness, and at the end there will be judgment. 1 John 5:17: All unrighteousness is sin. GOD’S JUDGMENT IS A MAIN THEME OF THE GOSPEL. YOU CANNOT REALLY UNDERSTAND THE GOSPEL UNTIL YOU HAVE AN UNDERSTANDING OF JUDGMENT. AND I WANT TO POINT OUT TO YOU THAT THE APOSTLES, WHEN THEY CAME WITH THE GOSPEL—ESPECIALLY TO UNREACHED PEOPLE—THE FIRST THING THEY SPOKE ABOUT WAS JUDGMENT, NOT FORGIVENESS. EXAMPLES: Acts 10:42-43; Acts 17:30-31; Luke 24:46-47 (JESUS PREACHED ONE WORD IN Matthew 4:17: REPENT). Without this preaching [ABOUT JUDGMENT], it is a FALSE GOSPEL.”

See:  Derek Prince – Sin, Righteousness & Judgement

https://jrichardduke.com/2016/01/18/derek-prince-sin-righteousness-judgement/

See also (click and open):

God’s Doctrine of hierarchy, the violation of which is blasphemy; doctrine of God our Savior Jesus Christ (Denying ungodliness, going through sanctification and living a sober life)

The doctrine of God our Savior must be taught