We Have A Baptism Becuase of God's Grace
Levitcus 16 shares the ritual the priest performed before entering into the presence of God. While it was more pinpointed to those who would have duties within the Tent of Meeting, the bathing and consecration was apart of God's command. The Old Testament will always be the half of the Bible whereas God was concealed and in the New Testament, God is revealed.
The revealing of Jesus (God's Son) was through John the baptist. Baptizing a chosen race of people in the Jordon River. He was a voice crying out in the wilderness for those to repent while Jesus walked among us as He prepared the way of His coming. Jesus came to John to fulfill scriptures being baptized for the repentance of sins, as a human dwelling among us. However, once Jesus carried all our sins to the cross, we now baptize in the name of the triune God (Father, Son and Holy Spirit). see Matthew 28:19
Baptism is for those who believe and in this new way of life in faith mimic what Jesus have done according to scriptures. Jesus was baptized and so we should want to display in our discipleship, the Christ like tendencies as a priestly race chosen by God. see 1 Peter 2:9
We are ultimately being baptized into His death, burial and resurrection.
1 Peter 2:9 Amplified BibleBut you are A CHOSEN RACE, A royal PRIESTHOOD, A CONSECRATED NATION, A [special] PEOPLE FOR God’s OWN POSSESSION, so that you may proclaim the excellencies [the wonderful deeds and virtues and perfections] of Him who called you out of darkness into His marvelous light.
Matthew 28:16-20
16 Then the eleven disciples went away into Galilee, into a mountain where Jesus had appointed them.17 And when they saw him, they worshipped him: but some doubted.18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.