Baptism as it relates to the Son represents the grace of Christ in his coming for our sakes, his dying for our sakes and his rising for our sakes, together with all other aspects of his redeeming activity. He was not an unwilling partner in the work of redemption. It is not as though an uncaring Father sent him irrespective of his own will in the matter. The Father loved his Son and suffered the pain of his Son ,the Son loved his Father and suffered the pain of his Father. They were in total harmony as to what had to be done in order to achieve the divine purpose for fallen man. It was the Son of God who loved us and gave himself up for us (Gal 2.20), the Son of God who loved the church and gave himself up for her (Eph 5.25), the Son of God who laid down his life for us thereby showing the true nature of love (1 John 3.16). Just as the Father's action was sheer grace, grace upon grace; so the Son's action was sheer grace, grace upon grace. Baptism in the name of Christ signifies this grace.
It will be seen from the above that baptism is intimately bound up with the death and resurrection of Christ. Now here is that made more clear than in Rom 6.3f where we are told by Paul that baptism is baptism into his death in order that, as he was raised from the dead, we also might live a new life. The real baptism is Christ's death and resurrection. Water baptism is but the outward sign of which Christ's death and resurrection are the reality. The metaphorical use in Mark 10.37ff 37ff where he speaks of his own baptism, i.e. "the baptism I am baptised with", and in Luke 12.49f when he tells the disciples, "I have a baptism to undergo" is the primary use.
Water baptism signifies Christ's death and resurrection and it signifies our death and resurrection. It signifies our identification with his death and resurrection. Through baptism we are baptised into his death, and through his resurrection we are raised to new life. It is well to remember that here also there is a primary and a secondary signification. Of primary importance is that water baptism signifies the death and resurrection of Christ. Of secondary importance is that water baptism signifies our death and resurrection; the second is entirely dependent upon the first. Bromiley puts this particularly well.
"It is an unfortunate reversal of the gospel message, or at least of the gospel emphasis, if in baptism we allow our own dying and rising again to occupy centre stage and push the dying and rising of Christ out into the wings. We are not to think that ours is the real baptism, and then apply the term in a transferred or figurative sense to the reconciling work of the Son. The ruth is that the reconciling work of the Son is the original baptism and our own dying and rising again with Christ is the copy and reflection. The proper baptism declared in every baptism is the vicarious dying and rising again of Christ in which expiation is made for sin, reconciliation is effected, new life is inaugurated, the covenant of God with man is restored, the election of the Father is fulfilled, and the divine purpose of grace is thus realised in spite of man's sin and fall."