Pentecost, which is the Festival, is a day of first fruits, of God’s first fruits harvested from the crop of the earth. What we can take away from it is knowing God's unending love for humanity.
The festivals are given to remind people that God is an active force and is gathering people. There is a rescue and a harvest, often when people or nations are at their lowest point. We were once slaves separated from God. As there are first fruits, more will follow. There will be universal opportunity.