The readings for the day of Pentecost are taken from Numbers 11:24-30; Acts 2:1-21; and John 17:1-11. All three lessons center on God’s promise to send His Holy Spirit to us.
Numbers records how God put His Spirit on seventy elders so they could help Moses lead and care for the Israelites. Joshua was jealous for Moses when these men prophesied, which was a witness to the Spirit of God in them. Moses wished that everyone had the Spirit of God in them, which is what Pentecost celebrates.
Acts is a history of the working out of the gospel in time and space. Pentecost was a celebration of the first fruits of the harvest, which is parabolic: on this day the everlasting first fruits of God’s redeeming work among people was evident.
The long-playing version of the Lord’s Prayer is the lesson from John. Jesus’ prayer revolves around several essential words; one of them is union/unity. Jesus bore away the curse of the law. The gospel of Jesus reverses the curse of Babel; the love of God has always been and will always be for everyone and for all. God proves this by granting His apostles the ability to speak to people in their various native languages, even though they could all understand Greek.