The Lord commanded that three annual festivals be celebrated in His honor. These festivals were:
1) The Feast of Passover
2) The Feast of Pentecost
3) The Feast of Tabernacles
The Lord may have had other reasons for commanding these festivals, but several reasons seem apparent:
1) To perpetuate remembrance of what God had done.
2) To keep them faithful to the Lord
3) To put seasons of rest and celebration in the annual calendar
4) To offer instruction, as the appropriate Scripture was read at each festival.
5) To renew their corporate identity as they came from all over Israel to the Temple to celebrate together.
6) To pass on the spiritual legacy of God’s people to the next generation.