We told our son that when he turned four he would be bigger. Shortly after his birthday we saw him at the kitchen table flexing his arms and saying "Bigger. Bigger. Bigger." He was pumping himself up - like a Reebok shoe.
There are times we think of faith the same way. We think that we are the ones that can increase our faith or make it stronger. But this is man's idea.
Faith is a gift of God. One given by Him, Exercised by Him, Kept alive by Him. All these things happen in our heart and mind, but the Holy Spirit is the One who is active in this work.
Then how does faith grow? The way God has revealed in His Word.
You can see it in the Psalms. A pattern. A cycle. It is the cycle of faith growth, or spiritual development. And it has three players.
The Holy Spirit
The Word (Christ the Son of God)
Nope - didn't guess it.
WHAT!? Are you sure?
Take a look at how it works. In Latin its called oratio, meditatio, tentatio - or in English - prayer, meditation, temptation/trial.
Prayer - requests and supplications to God - lead us into His Word for His answer. After having this seed (Word) sown, the devil comes to try and take it away. He does this in a variety of ways, most of which make something miserable - whether it is "not having" that thing you shouldn't have (temptation to sin) - or taking away something that you liked (sacrifice).
The incredible thing is that when we face trial, where are we to go? To God in prayer. Our plight pushes us back into prayer, back into God's Word. The Devil's involvement serves God's purposes - not the Devil's. But he can't help himself. God is using him against himself - priceless.
Let's take a look at a specific psalm to see what I mean.
How long, O LORD? Will you forget me forever? (Obviously the psalmist is undergoing trial here)
How long will you hide your face from me? (Yet he calls out to God in prayer)
How long must I take counsel in my soul and have sorrow in my heart all the day? (Sin is the issue)
How long shall my enemy be exalted over me? (The unrighteous have it good here - believers wait)
Consider and answer me, O LORD my God (I turn to you in prayer)
light up my eyes, lest I sleep the sleep of death (I deserve death for my sin)
lest my enemy say, "I have prevailed over him," (The Accuser [Satan] is saying this already)
lest my foes rejoice because I am shaken. (They are already celebrating in my face - save me)
But I have trusted in your steadfast love (Enter the Word - God's Word of forgiveness has broken in)
my heart shall rejoice in your salvation (Your Word promises me salvation, and I know I can trust it)
I will sing to the LORD (The psalmist has gone from trial through prayer/meditation to thanks)
because He has dealt bountifully with me. (WOW! The Word of the LORD stands forever - it is your defense - your fortress - your shield - and will always defeat your enemies - those who want to take you into greater sin and death.)
Neat right! God knows what He is doing. Just as a tree pushes its roots deeper after a windy day, the Christian pushes closer to God - His Spirit and Word - after trial and temptation. God is not angry with you - He has open arms of grace, and He calls you into them when you are frightened by the devil, your sinful flesh and death - even when those things speak the truth to you - like you are a sinner, or you are going to die. The Word of Christ is more powerful and it wins.
So you have no need to flex your arms and say "Bigger. Bigger. Bigger" about your faith. Get into God's Word, and pray that Word back to God. He will sustain you in this life.