According to Bart Ehrman, the Synoptic Gospels teach that the human Jesus was at some point ‘exalted’ to a divine status, but not that he was pre-existent.

But, responds New Testament scholar Simon Gathercole, this is to ignore the significant number of ‘I have come’ statements found on the lips of Jesus.  Here are some of them:

And when Jesus heard it, he said to them, “Those who are well have no need of a physician, but those who are sick. I came not to call the righteous, but sinners.” — Mark 2:17 (See also Matt. 9:13 and Luke 5:32; Luke adds “to repentance.”)

“Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.” — Matthew 5:17

“I came to cast fire on the earth, and would that it were already kindled!” — Luke 12:49

“Do not think that I have come to bring peace to the earth. I have not come to bring peace, but a sword.” — Matthew 10:34 (see also Luke 12:51)

“For I have come to set a man against his father, and a daughter against her mother, and a daughter-in-law against her mother-in-law.” — Matthew 10:35

“For the Son of Man came to seek and to save the lost.” — Luke 19:10

Gathercole explains the significance of these passages:

I would suggest that the natural sense of these sayings is that they imply that Jesus has come from somewhere to accomplish his mission. (Jesus is not talking in each case about how he has arrived in a particular town, having “come,” for example, from Nazareth to Capernaum.) When one examines these sayings of Jesus, the closest matches with them in the Old Testament and Jewish tradition are statements that angels make about their earthly missions (within the Old Testament, see, e.g., Dan 9:22–23; 10:14; 11:2). I found twenty-four examples in the Old Testament and Jewish tradition of angels saying, “I have come in order to . . .” as a way of summing up their earthly missions. A prophet or a messiah in the Old Testament or Jewish tradition never sums up his life’s work in this way. I am not for a moment suggesting that Jesus is viewed as an angel in the Gospels, but rather that he is seen as having come from somewhere to carry out his life’s work, namely, from heaven. Ehrman insists that if you read Matthew and Luke carefully, “you will see that they have nothing to do with the idea that Christ existed before he was conceived.” But I think if you read Matthew and Luke carefully in the light of their Jewish background, you can see that they have everything to do with Christ existing before he was conceived, before he “came” to embark on his earthly mission.

What Did the First Christians Think about Jesus?” in How God Became Jesus, edited by Michael F. Bird et al. Grand Rapids, MI: Zondervan, 2014.  As summarised in Evidence that Demands a Verdict, (2017 ed.).