Jesus said that if we have “faith as a mustard seed,” we can move a mountain. (See Matthew 17:20.) It is not the quantity of your faith, but rather the quality, that matters. Faith is given to those who are realistic and humble.
Why does God give you a specific measure of faith? (See Romans 12:3.) Because He has a specific place for you in the body of Christ. He has ordained you to serve a specific function as a specific member of the body of Christ. The faith He has given you is designed for your position in the body. If God wants you to be a hand, He will give you “hand” faith. If He wants you to be an ear, He will give you “ear” faith. If He wants you to be a toe, He will give you “toe” faith. But if you are a toe and you are trying to be a nose, there will be a complete imbalance between what you are trying to do and the faith that you have. The reason is not that you do not have enough faith, but that you are trying to use your faith for something for which it was not meant to be used. It was given for the specific job and place you have in the body of believers.
My hand does a wonderful job as a hand. It opens my Bible, turning the pages. It does most everything I ask of it. But if should I try to do those jobs with my foot, I would be in trouble.
If you are always struggling for faith, you are probably trying to do the wrong job. You are a hand trying to be a foot, or a foot trying to be a hand. This is God’s way of guiding you into your place.