Mustard seed faith is persistent faith. It continues to grow and become productive because it never gives up. It is the sort of faith exercised by the importunate man who kept knocking on his neighbor's door late at night until he got a response. "I tell you," Jesus said, that "even though he will not get up and give him anything because he is his friend, yet because of his persistence he will get up and give him as much as he needs" (Luke 11:8). Jesus also illustrated mustard seed faith in the parable of the oppressed widow, a parable He gave specifically "to show that at all times [the disciples] ought to pray and not to lose heart" (Luke 18:1). When the widow would not take no for an answer, the godless, indifferent judge finally gave her "legal protection, lest," he said, "by continually coming she wear me out" (v. 5). "Hear what the unrighteous judge said," Jesus went on to explain; "now shall not God bring about justice for His elect, who cry to Him day and night, and will He delay long over them? I tell you that He will bring about justice for them speedily" (vv. 6-8).

If ye have faith as a grain of mustard seed, which, as he says (Matt 13:32), "is less than all seeds." He means a faith real and trustful, though it be small and weak. The phrase is proverbial, expressive of littleness and insignificance. The mustard seed is quite little, but, grown in favourable soil and under sunny skies, it becomes, as it were, a tree among herbs, so that birds may nestle in its branches. To it faith is compared, because, small at first, it contains within itself power of large development and increase; from minute grains copious results are produced.

The mustard seed was the smallest seed known. But like the mustard seed that grew into a large garden plant (13:31-32), even a small "seed" of faith is sufficient. There is great power in even a little faith when God is with us. If we feel weak or powerless as Christians, we should examine our faith, making sure we are trusting not in our own abilities to produce results but in God's. If we are facing problems that seem as big and immovable as mountains, we must turn our eyes from the mountain and look to Christ for more faith. Then, as Jesus promised, nothing will be impossible. It is not the "amount" of faith that matters; rather, it is the power of God available to anyone with even the smallest faith. We cannot fail when we have faith.