In this passage, Luke sets the stage for Jesus' final act -- his journey to Jerusalem, where he will be welcomed with great rejoicing and five days later hung on a tree to die.
There's some disagreement about how much Jesus might know about what is to happen to him. Some folks, of course, say that with his divine foreknowledge he knew every detail of what was to happen. Some say that, because he was also human, he had some idea that this final confrontation with the Sanhedrin would lead to his death but not a second-by-second itinerary. In this second understanding, Jesus obeyed God because that was part of his mission and God called him to Jerusalem. He had faith that God would vindicate him, but in his human limitations he may again not have known the exact means God would use.
Whichever way you believe, there are two key lessons we can draw from how Jesus begins his journey. One is the aforementioned obedience. If he foresees his death or only suspects it, either way he obeys God in all things, showing us how we as human beings are to live our lives.
The other is something I'll call focus, and it's represented by the way that Luke says Jesus "set his face" towards Jerusalem. We might say we "set our sights" on something to get the same idea across. We have a goal and when we focus on it, we hold that goal before us and ignore distractions. Now that Jesus approaches the most important part of his work, he will keep it and only it before him. I can't say for certain, but perhaps this is why the Samaritan village rejects him. Verse 53 says "they did not receive him, because his face was set towards Jerusalem." If Jerusalem was his goal, maybe he wasn't willing to stop and teach them, or heal and perform miracles. Thus rebuffed, the Samaritan village responded in kind.
Whatever the reason, the village won't receive him, so James and John want to lay the smack down upon it. We're just told that Jesus "rebuked" them, and the nature of the rebuke is left to our imagination. I'd imagine that Jesus might say if he wasn't going to turn away from his Jerusalem goal in order to heal and teach at the village, then he sure wouldn't turn away to blast it from existence.
As he travels, a man comes to him and offers to follow him. Jesus warns him that those who follow him have no real home while they do -- and frankly, this is a pretty middling hardship compared with what awaits Jesus and later on, many of the apostles themselves. Apparently, it deters the man -- he will allow the hardships of following Jesus to distract him from the call to follow Jesus.
Then Jesus calls to a man to follow him, but the man wants to wait to bury his father. Some folks suggest the man's father wasn't dead, and he was suggesting that he needed to wait until his family obligations were over. In that case, Jesus' rebuke seems a little milder, because the man may have been deferring Jesus' call for many years and Jesus will have none of that. But even if the man meant that he needed to bury his father right away, Jesus' answer would be the same.
It's the same to the man who says he wants to say goodbye to his family before following Jesus. See, neither of these things are in any way bad, in Jesus' culture or our own. We have obligations to our families and friends, and we can't just ignore them for whatever we might want. Burying your father is a proper and honorable thing. But it's not going to Jerusalem. Letting your family know where you will be is a good thing. But it's not going to Jerusalem.
I've found that in my own faith life, as I've grown older, I am less and less likely to be distracted by "things of the world," although I've still been known to get a pang or two from them. What distracts me far more often are good things, things that aren't bad in any way. But even those good things can pull us from following Christ.
My denomination adopted a mission statement some years ago that said our mission on earth was to make disciples of Jesus Christ. I don't know how many of our churches -- including churches I've led -- have used that idea as the standard for measuring our activities. It's not that we have to cut everything that doesn't overtly make disciples. Some of it we should, but other things may need re-thought so we can see how they work to make disciples or how they might be retooled to do so.
Jesus closes with a metaphor drawn from farming done in his time. No one, he says, who puts a hand to the plow and then looks back is fit for the kingdom of God. Someone who plows without looking at the ground ahead does not plow a straight furrow, and that won't work. That may sound discouraging, but read it again -- what might we do if we have indeed erred and "looked back" when we've taken up the plow?
We can look forward again. We can set our face on Jerusalem as well, and it holds no terrors for us, for our Lord has already been there and prepared our welcome.