Leviticus 23 is God's divinely directed calendar. God tells Moses and the nation of Israel to celebrate His appointed "holy convocations" or sacred rehearsals to proclaim Him among the nations. The first is the Sabbath or Shabbat, a weekly reminder of rest. The remaining 7 feasts are annual.
The first of the annual festivals is Pesach or Passover, a remembrance of how the angel of death spared the Israelites who obediently covered their doorposts with the blood of a lamb. However, it also pointed forward to a NEW passover lamb, Jesus Christ whose shed blood would redeem all who accepted it back into fellowship with God. The second annual feast is HagHaMatzot or the Feast of Unleavened Bread. This was celebrated the day after Passover began and was a reminder of the unleavened bread that the Israelites took with them as they escaped Egypt, unleavened because there was no time to let it rise. It also looked to the future, to the Bread of Life, to the one who was sinless (no leaven), whose body would be broken, just as the bread was, to provide for our salvation.
Which brings us to the third of the annual festivals, the Feast of Firstfruits or Yom HaBikkurim. Pesach began on the 14th of Nisan, the 15th of Nisan was HagHaMatzot and on the 16th, the 3rd day of Passover Israel was told to celebrate Firstfruits. They were to celebrate the first part of the harvest in the Promised Land, the land God promised them. Firstfruits was also meant to be the future celebration of the Messiah's resurrection. Jesus blood was shed on the first day of Passover, His sinless body, the bread, was broken and in the grave on the second day of Passover, the Feast of Unleavened Bread. Then, against all odds Jesus is resurrected on Firstfruits, the third day of Passover. Three festivals, holy rehearsals that God had ordained centuries before suddenly given new life. Jesus was the first of the resurrected, the first of many, a firstfruit.
These three plus one more are Spring festivals and then there are 3 Fall festivals. What could these remaining 4 point forward to? Wasn't Jesus' earthly ministry completed in His resurrection? Check back to find out.