"Fully come" — the timing was God's. Pentecost was the Jewish feast of weeks, fifty days after Passover. Christ had died at Passover. The pattern was set in the calendar of God before any of them were born.

"One accord in one place" — unity preceded the outpouring. The Spirit did not arrive on a divided room.

Three things together: filled, spoke, given utterance. The Spirit produced the speaking; the speaking was the evidence of the filling.

The "tongues" here were known human languages (verses 6-11), enabling the gospel to be preached to people of every nation gathered in Jerusalem. The first miracle of the church was a missionary miracle.

Quoted by Peter from Joel 2:32. The promise is universal — whosoever. No ethnic, social, or moral qualification beyond the calling.

Paul will repeat this in Romans 10:13. The whole missionary expansion of the church flows from this one verse.

The climax of Peter's sermon. Two claims about Jesus: Lord (sovereign) and Christ (Messiah). The same Jesus they crucified.

The accusation is direct: whom ye have crucified. Peter does not soften it. True gospel preaching names what sin has done before announcing what grace has done.

The first response Peter required when his hearers asked "What shall we do?" Two acts: repent (turn around), be baptized (publicly identify with Christ). Two gifts: remission of sins, the gift of the Holy Ghost.

The pattern persists through the rest of Acts. Every recorded conversion includes both faith/repentance and baptism. The two are not separated in the apostolic preaching.

Four pillars of the first church: doctrine (truth taught), fellowship (life shared), breaking of bread (the Lord's Supper), prayers (corporate prayer). Any church missing one of the four is unbalanced.

They "continued steadfastly" — not one Sunday a week but daily and consistently. The first church was a daily reality, not a weekend event.