The apostles said to the Lord , 'Increase our faith.' Their request seems to come from nowhere. It is all the more striking because of the language Luke uses. The word 'Lord' is repeated in the next verse but the use of the words 'apostles', and 'faith' is also significant.
Although Jesus chose twelve and named them apostles,we don't hear the term 'apostles' that much in Luke. He says 'the twelve' more often, and most often he uses the term 'disciples'. He calls them apostles as they return from the missionary journey (9.10), when they sit at table with Jesus on the night he was betrayed (22.14), and when the women bring news of the empty tomb and resurrection on the first day of the week (24.10). But this occasion is significant because here the apostles are proactive.
The word 'faith' gets used sparingly as well. In fact at this point he has only used the word 'faith' just five times. It describes a disposition, something close to our word faithfulness. Whether it is the men who lower their crippled friend through a roof (5.20) or the centurion who had a slave at the point of death, who sends others to Jesus with the message which we repeat in the Mass, 'I am not worthy to have you come under my roof,' (6.6), or the repentant woman in the house of Simon the Pharisee (7.50), or the woman who touched the hem of his garment (8.48), it is their faith which Jesus sees.
By contrast, when the storm on the lake threatens the safety of the disciples, so that they wake him up he says to them, 'Where is your faith?' (8.25). Faith is not faith if kept in reserve for emergencies. Faith is lived daily and shapes the way we think and behave. It is about receptivity to God's presence in our daily lives and it is seen in our faithful behaviour.
At this stage the apostles are beginning to see their own limitations for the task ahead. It is no accident that this request follows on two sayings: one concerning apostolic care of the vulnerable; the other the need to forgive readily. This is how the disciple, and especially the apostle, should live each day. Each day is to be lived in the presence of the Lord whose 'mercies never come to an end' and 'are new every morning' (Lam 3.23). 'Be merciful, even as your Father is merciful' (6.36). Here it is the apostles who recognise their need for a stronger and deeper faith.
The Greek text can actually mean 'add to us faith.' The request is a reminder that the source of our faith and that of the apostles is the Lord himself.
Luke often uses the roles of the master and the servant or slave to talk about discipleship, faith and faithfulness. Here the point is that you can't expect a reward if all you are doing is your duty. A small landowner would have had a single slave whose duties included work in the fields by day and in the home by night. In that social contract the word translated as thanks or gratitude does not mean politeness or manners but means simply that the Master does not owe the slave anything for his obedience. Again sometimes a lot is said to turn on the particular word which is translated as unprofitable or unworthy but really it can simply means a slave or servant to whom nothing is owed (17.10).
The bottom line is that obedience is not a means to some reward. It is simply what being an apostle and a disciple or is about. The question 'Who is the greatest' (9.46; 22.24) should find no room in the heart of a true disciple.
We should not expect much reward for what we do and yet the Gospel and the faith the apostles have handed on to us promises much. Jesus talks about another master who leaves his servants in charge while he is away at a wedding feast and when he returns finds his servants faithfully keeping watch. Of him Jesus says, 'he will gird himself and have them sit at table and he will come and serve them' (12.37).
George Herbert said much the same thing in his poem 'Love',
'And know you not, says Love, who bore the blame?
My dear, then I will serve.
You must sit down, says, Love, and taste my meat:
So I did sit and eat.'