Faith is not something tangible to be taken like medicine. It is an attitude of trusting and believing. But even our ability to believe is a gift from God. No matter how much faith we have, we never reach the point of being self-sufficient. Faith is not stored away like money in the bank. Growing in faith is a constant process of daily renewing our trust in Jesus.
Jesus was telling the disciples that they would face difficult situations that could be resolved only through prayer. Prayer is the key that unlocks faith in our lives. Effective prayer needs both an attitude-complete dependence-and an action-asking. Prayer demonstrates our reliance on God as we humbly invite God to fill us with faith and power. There is no substitute for prayer, especially in circumstances that seem unconquerable.
Commentary from The One Year NIV Devotional New Testament, (2003), Tyndale House Publishers, April 15.