Growing in Faith

This Sunday's reading from Luke 17:5-10 appears to contain two separate teachings from Jesus,

The apostles said to the Lord, ‘Increase our faith!’ The Lord replied, ‘If you had faith the size of a mustard seed, you could say to this mulberry tree, “Be uprooted and planted in the sea”, and it would obey you.

‘Who among you would say to your slave who has just come in from ploughing or tending sheep in the field, “Come here at once and take your place at the table”? Would you not rather say to him, “Prepare supper for me, put on your apron and serve me while I eat and drink; later you may eat and drink”? Do you thank the slave for doing what was commanded? So you also, when you have done all that you were ordered to do, say, “We are worthless slaves; we have done only what we ought to have done!” ’

Notice that Jesus does not answer the apostles' demand directly. Instead he first tells them to see where their current state of faith stands and then launches into a story about a slave's standing and duty. 

It seems to me that Jesus is letting the apostles know that they have a long way to go, and that it is going to take a lot of hard work for their faith to increase. 

For most of us, growth in faith is a lifelong effort with lots of duties to attend to as we progress.