This is interesting to me because we've been celebrating the feast for over 8 years. Studying scripture and getting some actual hands on experiential understanding of Judaism , Hebrew Roots Movement , and the origins of Christianity is truly eye opening and gives the scriptures real context like it's never had before. But this was really only necessary because the Church is so devoid of meaningful teaching ; folks wouldn't get caught up in the loosing side of a 1900 year old argument if they had been better instructed from the beginning . People in the church that have not been inoculated against the very doctrines that Paul fought against, are not going to fair well when they are challenged by the same arguments. AS Jesus said search the scriptures , in them you think you have life , they are which testify of me!
Well let's take Shavuot from Judaism perspective the 50th day after Sabbath following the Passover , no new wheat could be eaten until this harvest celebration was performed in the land of Israel . The feast itself was a marker for the giving of the Torah at Mount Sinai . A couple of events happened that might concern us , one the people didn't want to hear the voice of God ( lets they die) , they wanted a mediator and sent Moses to "hear from the Lord and then do what ever he said" so Moses went up for 40 days and came down to the noise of sin in the camp , Moses broke the tablets of stone and 3000 people were slaughtered , the Aaronic priesthood was initiated because they took up the sword to kill the idolaters .
So something went horribly wrong here , the LORD himself spoke and that was too much for the people, they wanted a mediator and to not hear his voice , with Moses absent they rose up to play and the only a select group became priest when the original plan of God was that they be a kingdom of priest.
So some 1500 years later Jesus fulfilled the Passover , as the Lamb of God, and our mediator , our unleavened bread and the first-fruits from the dead , 50 days later at the feast of Shavuot the Shakinah glory of the LORD falls ( cloven tongues as of fire) on the 120 in the upper room in the temple and they began to speak with other tongues as the Spirit gave them utterance , and they were declaring the wonderful works of God. 3000 souls were saved that day , and this new kingdom of priest was born having the law written on their heart by the Holy Spirit.
Paul uses these two separate events, these two covenants as an allegory of Hagar and Sarah , one of works and one of promise , one of the letter and one of the Spirit , so Judaism is still under the law and in the hands of a mediator ( rabbis) , while true Christianity received the Holy Spirit by promise , through belief in Jesus as lord and savoir ( and the head of every man) and the infilling of the Holy Spirit (an adoption of Son-ship).
I don't know what day I got filled with the Holy Spirit , but I promise you it changed my life forever . If I never celebrated Shavuot or Pentecost , and still had the gift of the Holy Spirit , I would be as complete as I need to be in Christ , and that shadow picture that pointed to eternal life , is just a shadow, the substance is that vitality and the Spirit of the living God communing with me , covenanting with me , changing me ; securing me in his hand. The feast day is just a history lesson and a date on the calendar the substance is with me to the end of the earth everyday.
So what is more important? Receiving the holy Spirit or celebrating Shavuot?
I think Paul asked a really similar question ...
1O foolish Galatians! Who has bewitched you? Before your eyes Jesus Christ was clearly portrayed as crucified. 2I would like to learn just one thing from you: Did you receive the Spiritby works of the Law, or by hearing with faith? 3Are you so foolish? After starting in the Spirit, are you now finishing in the flesh?