This is a question that will arise at least once in a person's mind, and it is a fundamental question. Why? Because:
1. Baptism is a symbol of repentance of a sinner. Was Jesus a sinner? No. He was human, though.
2. Jesus is God. Then why did he need to be baptised - by a man of all things?
These questions and partial answers arose in this discussion by Dr. Jordan Peterson and a few of his esteemed colleagues, and I want to outline some of those answers and try to pull them and make sense of them from the Bible.
1. What was all this business with the baptism, then?
In the video above, Jordan and his colleagues notice the parallel between Jesus' baptism and the rescue of the Israelites from Egypt and the crossing of the Jordan. Why is this significant?
First of all is Jesus' mission. Jesus came to save the world from sin. Egypt represents the tyranny of sin. Under sin, God's people experience pain, suffering, injustice, oppression, death and most importantly, slavery. As a slave, you are compelled to serve many things including your base desires and external forces sometimes against your will and in a manner that is repugnant to morality and decency.
The Egyptian kings declared themselves to be deities and in a manner of speaking represented Satan as the originator and instigator of sin.
When God freed the Israelites from Egypt, He literally freed His people from the literal tyranny of a sinful ruler and a life in sin and signified that He will (would) eventually save His people across the planet from the tyrannical rule of the devil and a life in sin.
After that, He led them in a pillar which was a cloud by day and a pillar of fire by night to the brink of the Red Sea, and moved between His people and the Egyptians to provide cover for them even as He opened the sea for His people to cross. This was a symbolic first baptism of the Israelites.
Logically, if the Israelites went into the Red Sea after it opened and went across unmolested by the Egyptians, it figures that the pillar which God mentions to Moses as being His "Angel who would go before His people" later in Exodus went after them through the Red Sea, after which the Egyptians followed and were destroyed in the water.
In Christianity, thos refers to the process of justification, in which God saves His people from sin and Satan and is outwardly symbolised by the act of baptism.
Again, did Jesus sin? No. But He was made sin for us. How?
By hanging on the cross, He took on the curse that God pronounced by saying,"Cursed is the man that hangs on a tree," and by the laying hands on Him by humanity, confessing over Him and crucifying Him (I deal with this here).
Later, after forty years in the desert in which, again, Jesus leads them in the cloud and fire and God dwells among them in the tabernacle, these guys get to the Jordan and what does Jesus do? He gives instructions to Joshua on how they would cross the river, and how would this be accomplished?
The first thing that would happen was the ark of the covenant would be borne by four priests and as soon as their feet touched the Jordan, the water parted and as with the Red Sea, the Israelites crossed the Jordan as on dry land. Again, what happened God went before His people because His presence, symbolised by His glory, was with the ark of the covenant. Unlike in Egypt, the Israelites in the desert did the Lot's wife and craved severally to return to a life of sin which God had saved them from, culminating in the spies' rebellion which led to the punishment of all over twenties' by death in the desert except for Joshua and Caleb. It does not mean they were all lost, though, because Moses was later resurrected and taken to heaven and appeared to Jesus, Peter, James and John on the mountain.
Essentially, then, God symbolically sanctified (or purified and/or made holy) these people before leading them to the holy land. How does this apply to a Christian? After repentance and baptism, the Christian undergoes a process of transformation and renewal until his/her character is perfected and reflects the character of Jesus. Like a potter, God moulds this person and like a goldsmith he removes the sinful elements from him until he is purified. This usually happens by trial which is referred to as fire in the Bible. He then stops yearning for his life of sin and looks forward in faith to his coming salvation and delivery to the promised land which is heaven and eventually the new earth.
Back to Joshua. So these people were baptised again in a symbol of their sanctification which symbolises (I digress and am probably stretching this) their fitting to go to God's holy land. To the Christian, this wilderness represents various fiery trials and their eventual victory over them.
I digressed.
In both crossings, God goes with His people symbolically in the shadow of death and emerges with them victorious. In the first instance, He opens the way for them and protects them from an enemy who wants to reenslave them. In the second instance, He goes before them and destroys the enemy from before them. In both instances, He gives them the victory over sin and its ruler(s).
2. The second question is fundamental and is answered again in the same video in the same manner from the Bible. The doctor and his colleagues note that Jesus declares Himself to be the temple that He would destroy and rebuild in three days. I would like to note that the book of Revelation notes that there is no temple in the new Jerusalem because God is the temple of it. This is powerful because Jesus is declared here to be the high priest standing in the most holy place (I deal with this here).
So, how does this happen?
Seeing as Jesus, being sinless, needed no Justification, and being the fulfilment of the Jewish ceremonial law and sacrificial system, a priest would be needed to usher in this transition. By His baptism, then, He was symbolically sanctified by a priest to begin His work as high priest on behalf of humans as a human being and as the temple signified by the Jewish sanctuary. Both of these were sanctified by priests and John, being the son of a priest, was also a priest by inheritance and according to the law of God handed by Moses to the Jews.
The sanctuary was a signifier of the way back to God, the items of which symbolised Jesus, and at His baptism, He officially became the way back to God, and the link between God and man. His baptism and descent on by the Holy Spirit represents the culmination of God's promise to Adam, Abraham and Jacob. To Adam, Jesus would be the Lamb that God would give to be sacrificed by men to save them from sin. To Abraham, Jesus was God's holy Son, God himself, who God would sacrifice to save humanity. To Jacob, Jesus would be the link between God and humanity. All of these three promises came together at the point of Jesus' baptism and would be fulfilled by His death on the cross and eventual resurrection.
Baptism is a signifier of death and resurrection. Death to sin and resurrection in Christ. To be clear, this is the baptism by immersion which is what Christ underwent.
These are heavy thoughts. May God have mercy on me, a sinner.