Jesus is in 'outsider' territory again. The Samaritans were part Jews, but estranged from their 'half-cousins', Israel, at least from the days of the return from Exile. One of the problems that prevents us being received on Jesus' behalf today, received as little Christs, is that many of those we move among have been 'inoculated' against the Real Thing by past, part-experiences, half- experiences of Gospel that have left them thinking they're already Christian (so who needs to go any further?) For instance, we work among many who've received (or their children have) baptism as 'cheap grace' (Bonhoeffer) with no call for, or response to, the kind of commitment Jesus looks for in the second part of our passage. We can think of other examples. Our passage begins with those who are part-Jews, & moves on to those Jesus seems to see as wanting to be part-Christians. There's no way we can read this passage & not see the hard side of Jesus! Discipleship is not all beer & skittles. Those of us who would recruit people to Jesus via a lowest-common-denomination approach do well to heed what he says here.
The disciples' question about calling down fire from heaven is clearly a connection with 2KGS1 where maybe God's portrayed as a bit tough on the hapless soldiers who're zapped. Jesus knows the connection only too well. His disciples are looking not at a different God, but a different portrayal of God when they look Jesus in the face.
There's nothing wrong with any of the things the three would-be followers want to do before following Jesus, except their timing. God's time is always Now! Not tomorrow. Nor the next day. A strong sense of God's absolute right over us comes through here. Absolute right, & absolute Now!
In this little triptych, the first & last of the three would-be disciples are, on the face of it, volunteers, whereas the second, again on the face of it, is 'fronted' by Jesus. A question I've pondered, & tried to act on, for some years now: Would the quality of leadership in our church communities be improved if we directly fronted more people (having discerned whom it is we should approach) to take leadership roles, rather than calling for volunteers? I'm talking about leadership, mind you, & my answer, from experience, to my own question is: 'Yes'. Of course volunteers have their part to play, but when it comes to leadership, the issues are different. In any case, the two volunteers & one pressed man of our triptych all fail Jesus test of immediacy. God is always the God of Now, never of Later! How do we fare when Jesus applies that same test to us?