History of Pentecost/Holy Days

The day of Pentecost or the feast of Shavuot is one of the most important feasts in Judaism and great mark in Christianity.This is the day on which the God of Israel gave the law ,He descended on mount Sinai in the form of fire.On this great and wonderful day He wrote the law on stone tablets but in the first day of Pentecost of the new covenant He wrote His law on their hearts through His Spirit.In the new covenant He baptised them with the Holy Spirit and fire.On the first day of Pentecost in the Old covenant three thousand people were killed ,but in the New covenant first day of Shavuot three thousand people/souls were saved.Thus what the apostle Paul said in 2nd Corinthians ,the law kills but the Spirit gives life.Shavuot should be celebrated by the New testament Church but not under obligation or law, but under the spirit of celebrating the descent of the Holy Spirit on the church.