Baptism in the Bible (Matthew 3)

Mt 3:15 So Jesus replied to him, “Let it happen now, for it is right for us to fulfill all righteousness.” Then John yielded to him. 16 After Jesus was baptized, just as he was coming up out of the water, the heavens opened and he saw the Spirit of God descending like a dove and coming to rest on him. 17 And a voice from heaven said, “This is my one dear Son; in him I take great delight.”

John’s Baptism - Old Testament Baptisms
Flood 1Pe 3:21; Red Sea/Jordan 1Co 10; Tabernacle Cleansing Heb 9:10; Return from Exile cleansing: Eze 36:25 “Then I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your filthiness and from all your idols." John was to go “in the spirit and power of Elijah” who divided the waters of the Jordan (2Kgs. 2:8ff). John's baptism was to renew Israel through the Jordan (think of previous baptisms of Israel, Joshua, Elijah, Elisha, even Naman). John was in the wilderness beyond the borders of the Land (Mk. 1:5). He called Israel to cross the Jordan to enter the Land in renewal.
John’s baptism was a sign of a renewed Israel crossing into the Land to prepare for Messiah. Deuteronomy looks to a time when they “cross the Jordan” being led by Joshua (Dt. 4:21). The rest of the New Testament draws upon various threads of this crossing into Christ, through death and into resurrection life on the other side (Rom. 6:3-4; Col. 2:11-12).

Jesus’ Baptism - John's baptism of Jesus was in order to “manifest” (Jn 1:31) the Anointed One to Israel. Anointing restores fallen Man (‘adam) back into the presence of the Lord (Ps. 2:2). Like the baptism of priests involving a ritual washing, anointing, and vesting (clothing) (Ex. 28:41, Num. 3:3, etc.), so Jesus at baptism was appointed “by God as a high priest according to the order of Melchizedek” (Heb. 5:10; cf Luke 3:21, 4:18). Therefore Jesus “having received from the Father the promise of the Holy Spirit, He has poured forth” the Spirit on us (Acts 2:33). Our new identity is conferred in baptism, even as it was for Israel in the first crossing of the river (1Cor. 10:1-4). We are “all sons of God through faith in Christ Jesus for all of you who were baptized into Christ have clothed yourselves with Christ” (Gal. 3:26-27).