On May 15th, Christians will celebrate Pentecost Sunday for the 1,986th time since the very first Pentecost in 30 AD. But what exactly is “Pentecost”?
According to Acts 2:1-2, on the 50th day after Jesus rose from the dead, God’s Spirit appeared as flames of fire (2:3) and enabled Christians to speak in a way that people could hear the great things of God in their own languages (2:4-6). This is a reversal of the curse at the Tower of Babel (see Genesis 11:7 compared with Acts 2:6).
But why 50 days, and why are there tongues of fire settling on Christians?
Well, for Jews, the Feast of Weeks (Pentecost) celebrates the giving of the law at Mount Sinai. This is why: 45 days after Israel’s Exodus from Egypt (Exodus 19:1), Moses climbs up and down the 8,000 foot Mount Sinai. That difficult climb perhaps took a day each way. Then, on the 47th day, Moses warns Israel to ready themselves to receive the law three days later which would be the 50th day (19:10-11). “The 50th day” is what Pentecost means. Thus, Pentecost celebrates the day God gave the Mosaic Law to Israel.
Notice that on that day, God appears in flames of fire on Sinai (Exodus 19:18). According to 19:6, God promises Israel that they will be a kingdom of priests and a holy nation. God calls Israel to proclaim God’s greatness to all the nations of the world (Genesis 12:1-3, 22:8; Deuteronomy 4:6; Isaiah 49:6).
So how is that helpful to understand Pentecost Sunday today?
Well, just as Moses ascended Mount Sinai and gave the Mosaic/Old Covenant, Jesus, as the new/better-than-Moses, ascends Heaven and gives the Spirit who writes God’s law on our hearts in the New Covenant (Jeremiah 31:33; Hebrews 10:16; 2 Corinthians 3:6). Thus, Jesus has begun the transformation of his people into a kingdom of priests and into a holy, evangelistic nation (see 1 Peter 2:5-9; Revelation 1:6).
Just as fire rested on Mount Sinai, now flames of fire rest on the first Christians who are enabled to fulfill a higher, royal law (Romans 13:8-10; Galatians 5:14-6:2; James 2:8).
At Sinai, Israel received a law on tablets of stone--a law no man could fulfill, a ministry of grace (John 1:16-17) yet at the same time a ministry of death (2 Corinthians 3:7-8). Now God reveals his will through redeemed people, and the New Covenant empowers Christians to begin to walk in the ways of God.
God meant Israel to be a light to the world; Pentecost means that Christians, like little versions of Mount Sinai, reveal to the world the gracious rule of the living God.