

“When the day of Pentecost had come, they were all gathered in one place.” Acts 2:1
Pentecost exist before Pentecost. The Jews have always been celebrating the Feast of Pentecost. Traditionally it was mid-summer feast, marking the end of the barley harvest. In the time of Jesus, the feast celebrated the giving of the law and the covenant at Mt Sinai. It commemorates the events in Exodus 19-20. According Scriptures, the law was given fifty days after the Passover. As a text from the Hebrew liturgy of Shauoth says, “This day of the Feast of Weeks is the time of the gift of Torah.”
Pentecost is associated with the history of salvation (God’s work in our history in providing salvation). Just as at Mt Sinai, the people became a kingdom of priests’ through the law, here the people became a people of God, a Church, through the giving of the Spirit. The OT promises came to pass e.g. “I will write it in their heart...” (Jer 31:33), “A new heart I will give you...” “a new spirit I will put within you...” (Ezek 36:26-27). Paul said the same,
“The law of the Spirit of life in Jesus Christ has set me free from the law of sin and death.” (Romans 8:2)
If this is understood, then properly speaking, Pentecost is Salvation Day! Peter stood up and gave an evangelistic message. It is not just a day to celebrate the gifts or revealed/experienced power of the Spirit, but the birth and work of the Church.
Having understood this, the next thing we need to be reminded of is how mission became the first and immediate impact of the start of the church and how central the work and power of the Spirit is to all this. It is when the Spirit is working in our hearts and lives, that there is a ‘life’ to share. The Apostles were instructed by Jesus Himself and witness the death, resurrection and ascension. However, it is only after the Spirit came on them that they were able to do what the church is called to do.
What should our posture be? Just as the disciples were praying, we need to do likewise. Praying may seem such a ‘inactive activity,’ and yet it is always a prelude to some significant work of God in our lives. Just as the disciples were patiently waiting, likewise we should learn to wait as for the promises of God to unfold. Just as the disciples were boldly proclaiming (in tongues, in words), likewise we should not afraid to step out and exercise our faith. As some have noted, the gift of the Spirit were never meant to be domesticated, but to be used for witness.
And while at this, a heart of praise. That God in His wisdom and power works through our history to call us to Himself.