I have found a book in my library that explains how the title ‘Son of man’ in Matthew, Mark and Luke applies only to Jesus' earthly ministry to the Jews. Allow me to partially quote, after first setting the scene when initially, in Matthew’s gospel, Jesus did not first ask his disciples “Whom do men say that I am?” No, his first question was:
Whom do men say that I the Son of man am? (Matthew 16:13 KJV)
His disciples said that some Jewish men thought he was John the Baptist, Elias, Jeremias or one of the prophets. Then Jesus asks his disciples:
Whom say ye that I am? (Matthew 16:15 KJV)
That is when Simon Peter, inspired by divine illumination, cried out in response, not to an earthly manifestation, but to a heavenly revelation:
Thou art the Christ, the Son of the living God (Matthew 16:17 KJV).
Matthew refers to the title Son of man 32 times, applying it to Jesus before his death and then at his return, coming in the clouds of heaven with power and great glory, to reward every man according to his works. All the passages in Matthew, rendered in sequence, all apply either to the earthly ministry of the Son of man, or to his coming again. [1]
Mark makes 14 references to the Son of man, who had power on earth to forgive sins, who is Lord of the Sabbath, who came not to be ministered unto, but to minister, and who give his life as a ransom for many.
Just as in the case of Matthew, Mark passes from these texts which speak of the ministry, culminating in the betrayal, rejection, and slaying of the Son of man by the Jewish nation, and of his resurrection, to his coming again in power and great glory at the last day. [2]
Luke refers to the Son of man 26 times.
After the passages relating to the ministry of the Son of man to the Jews, Luke also passes without intermission to the coming again of the Son of man at the last day. This confirms that there is no bearing of the title and ministry of ‘Son of man’ on the ecclesia, the dispensation pertaining to this present age. [3]
Hence the Son of man cautioned them, whilst yet amidst the Jews on earth, with the following words: Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that shall come upon the earth, and to stand before the Son of man. For as a snare shall that day come on all of them that dwell on the face of the whole earth. [4]
In the three synoptic gospels, the title ‘Son of man’ is always used during, and applying to, Jesus' ministry on earth to the Jews. The only time the title ‘Son of man’ is used again is when Jesus suddenly descends from heaven to judge the world as the ‘Son of man’. This judgment includes the Gentiles, but only at that future moment in time.
‘Son of man’ was the title of the office in which God’s Son was sent to the Jews – God’s ancient people Israel – to turn that people to the kingdom, to bring them to the service of God, and to declare in their ears the long-promised grace sent to them from on high. All this was embodied in the Person and ministry of the Son of man.
Had the Jews received it, the blessing would have gone out from them throughout all nations upon the earth. But they rejected the kingdom, despising the Messiah. They refused the service, spurning the Servant of God. And they trampled underfoot the grace of God, denying that Just One. In a word, they crucified the Son of man, hanging him upon a tree. [5]
The last express reference to the Son of man is in Acts 7:56 when Stephen, after denouncing the Jews for slaying Jesus, “the Just One,” saw the Son of man standing on the right hand of God.
No more shall he appear to the Jews in this present life. Never again shall they hear his voice in the world that now exists. But as the ages run to a close, as the last day draws near, as the sands of time run out to the final grain, all the prophecies and all the signs of the coming of the Son of man shall come to pass. Then shall every last word that he spoke of himself in the gospels concerning the day of judgment most assuredly be fulfilled. [6]
Jesus, the light and life of the world, the Son of man, was despised and rejected by His own people. Yet Peter, through divine revelation within, saw Jesus in an entirely new light, not just as the Son of man, but as the Son of God. From all of this, I can only conclude that the title 'Son of Man' in the New Testament applies only to Jesus' earthly ministry to the Jews.
Source: ‘The Church – what is it?’ by John Metcalfe (The Publishing Trust)
[1] p 48
[2] p 49
[3] p 53
[4] p 54
[5] p 59
[6] p 62