Luke 3:21

Evidently John baptized Jesus after he had baptized many other people. Luke may have wanted to imply by this that Jesus’ baptism was the climax of John’s ministry. [Note: Marshall, The Gospel . . ., p. 150.] According to Luke this is the first of many important events that happened while Jesus was praying (cf. Luke 5:16; Luke 6:12; Luke 9:18; Luke 9:28-29; Luke 11:1; Luke 22:32; Luke 22:40-44; Luke 23:46). Only Luke recorded that the heavens opened while Jesus was praying, that is, a revelation from God followed. Luke had a special interest in Jesus’ prayer life. It showed His conscious dependence on His Father as a human being.

"Jesus’ baptism, like that of the people, was a single event in time; but his praying continued for his lifetime." [Note: Liefeld, p. 859.]

Perhaps this explanation accounts for the different tenses of the verb and the participle in this verse. Luke also may have mentioned Jesus’ praying to encourage his readers to do the same. The opening of the heavens indicated divine intervention into human history with revelation. God Himself had not intervened this way for many centuries. Luke’s original readers, with their background in Greek mythology, would have had a special interest in this intervention. The Greek gods supposedly intervened in human affairs occasionally. Moreover Luke’s frequent references to Jesus praying would have helped his original readers realize that Jesus was truly human and not just a god who had visited humans.

"In Luke-Acts times of prayer and worship are frequently the occasions for divine revelations to characters in the story. This is true of Zechariah (Luke 1:9-11), Anna (Luke 2:37-38), Cornelius (Acts 10:2-6), Peter (Acts 10:9-16), Paul (Acts 9:11-12; Acts 22:17-21), and the prophets and teachers of the church in Antioch (Acts 13:2). This is true also of Jesus. Jesus’ choice of the twelve is preceded by prayer, indeed, prayer through the whole night (dif. Matthew, Mark), in which Jesus is evidently seeking divine guidance for the choice (Acts 6:12). The transfiguration also takes place while Jesus is praying (dif. Matthew, Mark). . . . In Luke 22:40-46 also, if Luke 22:43-44 are an original part of the text, Jesus prays concerning his mission and receives a response through a vision of a strengthening angel." [Note: Tannehill, 1:56-57.]