When you realize how great and faithful his promises are to you, he can then live mightily and powerfully in you.

Then David said to the Philistine, "You come to me with a sword, with a spear, and with a javelin. But I come to you in the name of the Lord of hosts, the God of the armies of Israel, whom you have defied.
(1 Sam. 17:45)

Many years ago when Jesus appeared to me, he told me that if I would paint a picture of Jesus Christ bigger in your heart than the circumstances—bigger than the sickness, bigger than the devil— you would always receive your miracle. Real faith means to totally trust and rely on God. It is very easy to do, when you realize how big and great He is. He created this world with just his spoken word. He supernaturally fed and provided for the children of Israel in the desert for forty years. They called him el Shadai the God that is more than enough.

Sometimes we forget that He really is God Almighty and his Word states, "The righteous cry out, and the Lord hears, and delivers them out of all their troubles." (Ps. 34:17) You have to remember the greater one lives in you. His word further states in Romans 8:  

He who did not spare his own son, but delivered him up for us all, how shall He not with him also freely give us all things? Who shall bring a charge against God's elect? It is God who justifies. Who is He who condemns? It is Christ who died, and furthermore is also risen, who is even at the right hand of God, who also makes intercession for us.
(Rom. 8:32-34)

When you realize how great and faithful his promises are to you, he can then live mightily and powerfully in you. When that revelation becomes alive in you, then you can walk in the victory He paid for you with his precious love and blood. Your prayer and fellowship with the Father God and Jesus Christ is the only way to an intimate fellowship and a complete trust in him.

First Samuel 17:

Then David said to the Philistine, "You come to me with a sword, with a spear, and with a javelin. But I come to you in the name of the Lord of hosts, the God of the armies of Israel, whom you have defied.

This day the Lord will deliver you into my hand, and I will strike you and take your head from you. And this day I will give the carcasses of the camp of the philistines to the birds of the air and the wild beasts of the earth, that all the earth may know that there is a God in Israel.

Then all this assembly shall know that the Lord does not save with sword and spear; for the battle is the Lord's, and he will give you into our hands.”
(1 Sam. 17:45-47)