Luke 17 5 The apostles said to the Lord, “Increase our faith!” 6 He replied, “If you have faith as small as a mustard seed, you can say to this mulberry tree, ‘Be uprooted and planted in the sea,’ and it will obey you.
After Jesus tells his disciples that they must forgive their brother or sister up to seven times if they repent, the disciples wonder how they could have that much faith. And then they ask Jesus to increase their faith. Jesus uses the opportunity to explain more about the nature of faith. He explains that with faith it is not as much about quantity but quality. He uses the analogy of the mustard seed to show the results of true faith.
By using the uncommonly small mustard seed as an example, Jesus is speaking figuratively about the incalculable power of God when unleashed in the lives of those with true faith. Gotquestions.org
If faith is a gift of God, then we can't earn it. God takes our faith and uses it to accomplish his purposes. We know we are acting in faith when we look at the results and know that there is no way we could have produced them. That is why a life of faith is so humbling, we can't take credit for God uses it. In fact, faith is a testimony to God's greatness. The only way we can forgive someone so many times is by faith. In our natural man we could never do it.
Faith is a gift of God but we still need to exercise or use it. The writer of Hebrews says, "Without faith it is impossible to please God". Faith is trusting in God. Faith is trusting in God to do what we cannot do. The analogy of seed helps us to understand that as the tiny seed grows into a large plant, so our faith grows as it is rooted in God's Word.
So a question you might ask yourself today is, what is it in my life that only can happen through God's power? To access his power we need faith. A little faith goes a long way. After all when is the last time a mulberry tree obeyed you?