In Chapter 3, Luke presented a traditional story about what occurred around the time of Jesus' baptism; this story in the main agrees with what we read Matthew and Mark. But it is Luke who returns for a moment to that "coming of the Spirit" upon Jesus in order to explain a purpose for that coming. With the help of the Old Testament (Isaiah), Jesus describes what he will be doing in the rest of the Lucan Gospel. One the one hand, the concrete examples of liberation that Jesus offers are for the most part fulfilled; he did not, however, free prisoners from jail. On the other hand, with a more general phrasing Jesus describes his overall pressing task: to announce a year of God's favor. Considering the rest of the Gospel and its report of what Jesus said and did, one sees that the more accurate description of Jesus' work is that contained in the general phrase; within that, one is to put the concrete examples he cites from Isaiah. Thus, the most important result of Jesus' baptism is the offer of God's favor (to all), within which offer Jesus will perform mighty and merciful deeds which are freeing for those (relatively few) who receive them.
This offer of God's favor or love corresponds to and is defined by two further statements of Jesus early in his public life. First, he says that he has been sent to announce the Kingdom of God. Second, he says that he has been sent to call sinners to repentance. The second fits into the first as means does to end: that is, one will enjoy the presence of the Kingdom if one repents.
All of this means that, in the Lucan Gospel, Jesus means to offer entrance into the Kingdom of God through repentance, that this offer can be understood as a freeing from evil so that one may enjoy the good. Miracles, like curing the blind, are signs of what the Kingdom will do in the fullest way, when one can enjoy the fullest freedom to become one's perfect self in all aspects. That perfection is life forever with God. Miracles are sings that the power to make all perfect is already among us and urging us, by the show of loving power, to repent so as to enter the fullness of what God has in store for us. Jesus, as he cites Isaiah, will begin to free; the response he wants is repentance, by which we fully and truly become free.
That this work of Jesus concerns a 'year of God's favor' means to emphasize to Jesus' audience, which has felt the absence of God, that now God is ready to show again that love and favor which He has shown so often in the past, principally through covenants, chiefly, Abrahamic, Mosaic and Davidic covenants. He wants to be partners again, groom to His bride again. He calls now to us to come to Him. Jesus identifies himself here as the one who calls.
John Kilgallen, SJ