The Lord speaks to Moses and tells him that the people are to make offerings to the Lord. There are all sorts of offerings in the book of Leviticus and each one points to Christ.
The Son of God made flesh is born to be an offering, not just a lamb to take away the sin of the world but an offering that encapsulates all the offerings of Leviticus:
He is the Burnt offering, he will make atonement for the people. – Leviticus 1:3-17. “He shall lay his hand on the head of the burnt offering, and it shall ne accepted for him to make atonement for him!” (1v4)
He is the Grain offering, Jesus is the first fruits (Leviticus 2).
Jesus is the sin offering, He covers us with his blood (Leviticus 4)
Jesus is the guilt offering, he pays our debt and takes away our guilt before the Father. (Leviticus 7)
Jesus is the fellowship (or peace) offering, He brings us in fellowship with the Father. (Leviticus 3 & 7)
Jesus is born at Christmas to be an offering on our behalf and he will be a sweet aroma to the Father. “…it is a food offering with a pleasing aroma to the Lord” (3v5)
Christmas is about the Son of God being an offering that is a pleasing aroma to the Father on our behalf.