Shavuot is the actual biblical feast the Apostles celebrated at Pentecost when the Holy Spirit was poured out. It marked the giving of the Mosaic Law on Mount Sinai. And it foreshadows that day when God inscribes His Law on our hearts - through His Holy Spirit.
Each year on Yom Kippur, the High Priest chose two goats, one to symbolically carry the sins of the people into the wilderness, the other to be sacrificed on the altar to pacify God’s wrath over sin. He then entered the Holy of Holies of the Tabernacle and interceded before the Ark of the Covenant for his people for God to have mercy. About 1200 years after the Israelites celebrated the first Yom Kippur in the wilderness, Yeshua, who was without sin, became the true scapegoat, carrying our sin and putting it to death when He gave His life on the cross.