How do we know the significance of Pentecost for Christians?

The significance of Pentecost for Christians is profound, as it commemorates the outpouring of the Holy Spirit on the believers gathered in Jerusalem, leading to the formation of the Church. This event is described in Acts 2, where the apostles were filled with the Holy Spirit and began to speak in different languages, drawing a diverse crowd that heard the gospel in their own tongues. This miraculous occurrence was the fulfillment of Jesus' promise to send the Helper and it signifies the beginning of the Church’s mission to proclaim the gospel to all nations. Pentecost emphasizes the unity of believers, both Jews and Gentiles, into one body of Christ, as expressed in Ephesians 2:11-22, where Paul elucidates that through Christ, both groups are reconciled and given access to the Father by the Spirit, thus breaking down the dividing wall of enmity.