For by grace you have been saved through faith. Faith is the act by which we acknowledge our complete trust in God for our salvation. By faith, we believe that God's plan of salvation is sufficient to give us eternal life. For I say, through the grace given to me, to everyone who is among you, not to think of himself more highly than he ought to think, but to think soberly, as God has dealt to each one a measure of faith. First, let's specify that God has dealt to each one of us a measure of faith.
Nobody starts out with nothing.
And the apostles said to the Lord, Increase our faith. So then faith comes by hearing, and hearing by the word of God. It is through careful study of the Bible, in a spirit of humility and sincerity, that each one of us will learn to know God better, and then to trust Him more and more. Our faith in God and His plan of salvation will thus grow day after day. He asks us to believe in Him, and to place all our trust in His plan of salvation.