'Sound Doctrine'
Col 2:16-17 So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, which are a shadow of things to come, but the substance is of Christ.
Jewish Feasts are only a shadow of things to come.
Deu 16:16 "Three times a year all your males shall appear before the Lord your God in the place which He chooses: at the Feast of Unleavened Bread, at the Feast of Weeks, and at the Feast of Tabernacles; and they shall not appear before the Lord empty-handed.
Three times a year Jews must appear before God at His tabernacle (temple) for these feasts.
Note - the destruction of the temple of God in Jerusalem in 70 AD ended Judaism and all Jewish feasts.
1. Feast of Unleavened Bread
Lev 23:5-6 'On the fourteenth day of the first month at twilight is the LORD'S Passover. And on the fifteenth day of the same month is the Feast of Unleavened Bread to the LORD; seven days you must eat unleavened bread.'
After the Passover Lamb was sacrificed, all Jews must keep the Feast of the Unleavened bread for seven days.
The crucifixion of our Lord Jesus as the Passover Lamb started the new covenant. Christians must now abide in His Word the Bread of life, thus fulfilling the Feast of Unleavened Bread.
2. Feast of Weeks (Pentecost)
Lev 23:10, 15 "Speak to the children of Israel, and say to them: 'When you come into the land which I give to you, and reap its harvest, then you shall bring a sheaf of the firstfruits of your harvest to the priest... 'And you shall count for yourselves from the day after the Sabbath, from the day that you brought the sheaf of the wave offering: seven Sabbaths shall be completed."
The Jews must bring a sheaf of the firstfruits of harvest to the priest. *Our Lord Jesus was the firstfruits who rose from the dead* thus fulfilling the firstfruits of harvest.
1 Cor 15:20 But now Christ is risen from the dead, and has become the firstfruits of those who have fallen asleep.
Acts 2:1, 41 When the Day of Pentecost had fully come, they were all with one accord in one place... Then those who gladly received his word were baptized; and that day about three thousand souls were added to them.
The last day (50th day) of the Feast of Weeks will be the celebration of first harvest in the land. On Pentecost, the last day of the Feast of Weeks, the outpouring of the Holy Spirit resulted in most of those present receiving gifts of the Holy Spirit and also the first harvest of three thousand souls fulfilling the Feast of Weeks.
3. Feast of Tabernacles
Lev 23:34, 42 "Speak to the children of Israel, saying: 'The fifteenth day of this seventh month shall be the Feast of Tabernacles for seven days to the Lord... You shall dwell in booths for seven days. All who are native Israelites shall dwell in booths,"
All Jews must dwell in booths (tabernacles) during the Feast of the Tabernacle.
When our Lord Jesus was killed, His body (temple) was destroyed.
John 2:19, 21 Jesus answered and said to them, "Destroy this temple, and in three days I will raise it up"... But He was speaking of the temple of His body.
Christians are Tabernacles of God
John 20:22 And when He had said this, He breathed on them, and said to them, "Receive the Holy Spirit."
After His resurrection on the third day, He gave the Holy Spirit, thus making the physical bodies of the Apostles to be tabernacles (temples) of God, thus fulfilling the Feast of Tabernacles.