Some people come to faith when they are very young. That may have happened with you. So, their first faith is a “childlike” version of Christianity – “Jesus loves me.” And it doesn’t grow much after that. They become adults and have busy lives and children themselves; but their faith remains the “childlike” version that they got back at church camp or Vacation Bible School as a 10-year old.
When their adult lives get really complicated, they find that their growth in faith has not kept up with their development in other areas of life. They may still want to do the right thing, but they have no way to decide what that is.
You may have had that very experience. If it sounds familiar, then remember the story from Luke 17. The disciples have been following Jesus for a while. They have seen him do and say many things. He has taught them about forgiveness, and love of others, and the way of the cross, and much more – and, maybe, their early faith is waning. They know that they don’t measure up.
Perhaps, that sense of “not measuring up” caused them to ask Jesus to, “Increase our faith.” They realized their faith was a quart or two low! And what does Jesus do? He tells them the story (a parable) about the mustard seed – that tiny seed that can do spectacular things. Surely, the disciples took heart. They had hope because just a tiny bit of faith goes a very long way.
The key is this: it’s not a matter of how much faith you have. Having faith, some faith, in a very everyday manner, is enough. You don’t have to be a saint. If your faith is as large as a tiny mustard seed, that is enough.