Two important verses:
So faith comes from hearing, and hearing through the word of Christ. (Romans 10:17 ESV)
8 Indeed, I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ 9 and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith — (Philippians 3:8-9 ESV)
Faith means trusting, believing, confidence in, reliance upon. In our context we are talking about faith in Jesus Christ.
How do we get this faith?
The first verse tells us. Faith comes from hearing the word of Christ. To have faith I must read or listen to the words spoken by Jesus. Those are more than just the words written in red. They are the words of the Bible. Specifically, the words of the New Testament. True faith is our believing what Jesus has actually said. Not our own thoughts, opinions nor traditions.
What is the reward of this faith?
The second verse tells us. The reward is the righteousness that comes to us through faith in Jesus Christ. Through believing in Jesus, God grants us forgiveness of sins and declares us to be holy and acceptable in his sight. We are declared righteous in God’s sight as a result of our faith in Jesus.