I would like to present an atheistic bible study, an observation or interpretation, I believe explains the re-working of the original story of Jesus and John the Baptist by the authors of Matthew and Luke. This is with the understanding that Matthew and Luke use Mark in their compositions. In Mark Jesus is baptized into ( eis) the remission of sins. The preposition “eis” means from out of a state to into a different state or place. This preposition in Mark is redacted (re-worked or edited) by Matthew.
The statement of what the baptism is for in Matthew is dropped. We see the term “into the remission of sins’ added instead by Matthew to the pericope of the Last Supper. 26:28. There communion becomes for the remission of sin. Matthew creates a conversation where John the Baptist tries to prevent Jesus from being baptized and Jesus tells him to go on with it to fulfill all righteousness.
This answers the problem of why a sinless person would need baptism as in Mark and also makes John subservient to Jesus. This makes obvious the church is dealing with the fact that Jesus was a follower of John the Baptist and does not begin his ministry until John is arrested. The author of the Gospel of John will have Jesus baptizing and ministering at the same time as the Baptist and does not have Jesus baptized by John.
In Mark Jesus comes up out of the water and the Holy Spirit comes into ( again eis) him. Matthew changes this to the spirit descends upon ( epi) him. The idea of the spirit after baptism coming into a person is consistent with the idea in Acts 2:38: Peter replied, “Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit.
In Mark Jesus alone hears god saying that he is well pleased. In Matthew god addresses his pleasure to the crowds. Luke maintains Mark’s terminology about baptism, changes the adoptionistic reception of the Spirit into Jesus to a confirmation like Matthew to the spirit as dove comes down upon (epi) him. The change of the preposition by Matthew and Luke are intentional because of the theological implications and the addition of the infancy narratives wherein Jesus has the spirit from birth! Luke quotes mark and maintains gods announcement of pleasure to Jesus.
When one looks at the quoted OT verses in Mark 1:2f they are combined and perhaps reflect a pre-exiting proof text designed from Isaiah and Malachi not just Isaiah as stated. The pronouns are changed so that the verses can apply to the idea of the Baptist as precursor. Instead of “Behold I send my messenger before your face the original in Malachi 3:1 reads “I will send my messenger before me ( i.e.; God).” The change is from god talking to his prophet about his own coming to god talking to Christ about sending the Baptist before him. The messenger in Malachi was originally the Messiah and not the Baptist. The change is from god to messiah or Jesus in doing so and an example of a forged prophecy. Thus the preparing of the way of the Lord (Yahweh) shifts to a Messianic interpretation and the make straight his paths is substituted for the paths of our God.