Who is the “us” of Matthew 3:15 and what did Jesus mean by fulfilling all righteousness? Some view the “us” as the members of the Godhead while others believe it refers to Jesus and John.
The baptism of John called on the nation of Israel to repent and believe on the coming Messiah (Act 19:4). It was a mark of separation from the ungodly condition of the nation. John certainly enjoyed some popularity as “there went out unto him all the land of Judaea, and they of Jerusalem,” confessing their sins as they were baptised (Mar 1:5 KJV). Even the Pharisees and Sadducees came, but were found unworthy as they had not demonstrated the “fruits” that proved genuine repentance in their lives (Mat 3:8). Imagine, therefore, John’s surprise when Christ travelled the sixty miles from Nazareth to Jordan to be baptised. There was no repentance or confession necessary on His part!
Only Matthew tells us of the conversation that unfolded between the Baptist and the Lord Jesus at His baptism. John clearly recognised his inferior place before the superior moral worth of the Lord (cf. v11), and thus sought to deter Him. How could the servant baptise the Master? Though the Lord appeared to acknowledge the validity of John’s concern, He called upon him to allow it as being fitting (proper) for both John and Christ to “fulfil all righteousness.” This is no reference to “members of the Godhead” but rather a gracious acknowledgement of John’s part in the baptism and thus divine approval of his ministry. But what does it mean to “fulfil all righteousness”? Matthew’s Gospel is full of the theme of “righteousness,” using the word and its derivatives more than all the other Gospels combined. Why? A true king must be characterised by righteousness and build his kingdom on the same (Isa 32:1). Matthew’s use of the word emphasises ethical righteousness and conformity to the will of God. The Lord Jesus is therefore explaining to John that it is God’s will for Him to be baptised, as well as exhibiting the qualities of the true King. The Lord Jesus ever did, and identified with, that which was right. He was always faithful to the word and will of His Father (Psa 40:8).
No wonder the heavens literally burst asunder (cf. Mar 1:10) to express delight in the perfect Servant. There was no confession of sin before this baptism – the confession rather took place after in the form of a divine proclamation of the Father’s pleasure in His Son. The Spirit visibly descended “like a dove” in movement, officially anointing the Christ of God to public ministry by resting on Him (Act 10:38). The symbolic nature of the dove indicated a prospective ministry characterised by peace, purity and gentleness.
To what end, then, was the baptism of the Lord Jesus? Why was this a righteous requirement of His Father? In grace the Lord Jesus was divinely authenticating the ministry of John and identifying with a godly remnant that heeded his preaching. The subsequent descent of the Spirit identified Him as the true Messiah and Son of God (Joh 1:33-34). As a symbol of death, His baptism also prefigured the awful baptism of Divine judgment He would endure at Calvary (Luk 12:50).