Faith is used in the New Testament some 263 times as a whole word. In my reading, most of the verses seem to reflect a similar idea that can even be discerned through just a few of them. For the Christian, the term “faith” is used in the context of having confidence in a God whose existence is not doubted and, by extension, Jesus’ Godhood.
The existence of God is not the substance of the Christian’s faith, but confidence that God stays true to the promises and love He has for us. As for His existence, Jesus and Peter have a unique conversation in the Gospel, in which Peter confesses Jesus as the Messiah, the Son of the Living God. After this, Jesus tells him that this knowledge was not imparted to him by flesh and blood, but by the Father. Knowledge of God’s existence occurs through revelation and, not unlike Abraham, we have no other possibility, but to accept it. Where faith is only worth as much as the one on whom it is placed, God’s indisputable existence shows us that He is, indeed, worthy of such confidence. So, in being faithful one is living in accordance to the confidence with which they trust God’s ability to do what it is He says He will do.
To the one God who imparts faith into the heart of man, all glory, honor, and praise in the name of the begotten Son of the Living God, Jesus.