“the Holy Spirit descended upon him in bodily form like a dove”
Only Luke includes the phrase “in bodily form”. Jensen (Preaching Luke’s Gospel) makes the point that “Bodily descent has the character of permanence. The Spirit not only descended upon Jesus; the Spirit of God came in bodily form and it will remain upon Jesus.” He makes a contrast between Jesus and Israel’s “charismatic judges” on whom the Spirit of God descended temporarily.
The descent of the Spirit on Jesus can not be understood separately from Luke 4:18-19 where Jesus quotes Isaiah 61:1-2
“The spirit of the Lord GOD is upon me, because the LORD has anointed me; He has sent me to bring glad tidings to the lowly, to heal the brokenhearted, To proclaim liberty to the captives and release to the prisoners, to announce a year of favor from the LORD and a day of vindication by our God, to comfort all who mourn”
The descent of the Spirit upon Jesus was an anointing (and empowering) for his ministry on earth. At the same time, prior to this event at Nazareth, we are told: “Jesus, full of the Holy Spirit, returned form the Jordan and was led by the Spirit in the wilderness, where for forty days he was tempted by the devil” (4:1-2a). At the end of the temptation, we are told, “Then Jesus, filled with the power of the Spirit, returned to Galilee” (4:14a). Did Jesus’ “power” for his ministry come just from the descent of the Holy Spirit or from his successful battle with the devil in the wilderness? The answer is probably “both”. If we want to experience the power of the Spirit, it may mean that we have to do more than pray. We may have to enter into the battle with Satan — evil forces wherever they may be in our communities or within us.
Craddock (Luke, Interpretation Commentaries, p.52) writes: “The coming of the Holy Spirit does not make Jesus the Son of God; Luke has told us who Jesus is from the time of the annunciation. The Holy Spirit comes to empower Jesus for his ministry. He will soon be led by the Spirit into the desert (4:1), and then he will return ‘in the power of the spirit into Galilee’ (4:14).” Both the temptation story and the Isaiah quote indicate that Jesus’ Spirit-led ministry is to battle and defeat evil in whatever form it appears. And, that Spirit-led ministry continues after the ascension through “all flesh” upon whom God has now poured the Spirit.
21-22 After all the people…I am well pleased: These two verses are structured with primary and subordinate phrases. The primary phrases, by themselves, would form a sentence, literally translated, as follows: “It happened that the heaven was opened and the Holy Spirit came down and a voice came out of heaven.” The lines about Jesus’ baptism and his praying are subordinate clauses (genitive absolutes in Greek). They are not the main point of the sentence. The aorist tense probably indicates that the baptism had happened sometime prior to the praying. The present tense indicates that Jesus was still praying when the main actions occurred: the opening, the coming down, and the heavenly speech.
21 was praying: An element of the baptismal account found only in Luke. Lacking the description of Jesus coming out of the water, Luke is describing a prayer experience similar to the transfiguration (9:28) Luke regularly presents Jesus at prayer at important points in his ministry: here at his baptism; at the choice of the Twelve (6:12); before Peter’s confession (9:18); at the transfiguration (9:28); when he teaches his disciples to pray (11:1); at the Last Supper (22:32); on the Mount of Olives (22:41); on the cross (23:46).
heaven was opened: Does Luke intends to imply anything more than a means for the “coming down of the Spirit” and so that the “voice from heaven” might be clearly heard. In one way, heaven was opened earlier in the writing when the “multitude of the heavenly hosts” appear and praise God and then return to heaven (2:13, 15). The next time “heaven” is used following our text is in 4:25, which is part of Jesus’ sermon in the Nazareth synagogue. Jesus makes reference to the time of Elijah “when the heaven was shut up three years and six months, and there was a severe famine over all the land.” If the “shutting up of heaven” resulted in famine and all that goes along with that: hunger, sickness, death; could not the “opening of heaven” symbolize the coming of plenty, health, and life? The same word for “opening” (anoigo) is used in some variant readings of 4:17 (the better attested word is anaptusso = “unroll”), which takes place in the synagogue at Nazareth. Jesus opens the scroll and finds Isaiah 61:1-2. Possibly Luke intends that both the opening of heaven and the opening of the scroll allows God to make a declaration about Jesus.
22 holy Spirit descended: For Luke this is the same Spirit already at work in the gospel (cf. 1:15, 35, 41, 67; 2:25, 26). The implications of the anointing of the Spirit for Luke’s understanding of messiahship unfolds in the narrative of Luke 4:18 and following.