An interlinear Bible will note that the definite article "the" should appear before "faith," making this faith a specific kind or level of faith distinct from others. Anybody can have a spiritual faith in somebody or something—even in the Creator God—and still not have saving faith, the faith to which Paul refers here. Many believe in a Creator God yet do not know Him, do not understand His purpose, do not understand the extent of Satan's influence on them or the world, and do not obey God's commands. They are, in short, uncalled by the sovereign God and not as yet appointed to eternal life.
This saving faith appears frequently in Scripture:
» Colossians 2:7: ". . . established in the faith."
» I Timothy 1:2: "To Timothy, my true son in the faith."
» I Timothy 4:1: ". . . some will depart from the faith."
» I Timothy 5:8: ". . . he has denied the faith."
» Titus 1:1: ". . . according to the faith of God's elect."
» Titus 1:13: ". . . that they may be sound in the faith."
» Titus 3:15: "Greet those who love us in the faith."
» Jude 3: ". . . contend earnestly for the faith."
In each case "the faith" indicates not only a specific kind or level of faith but also a specific body of beliefs or knowledge from which faith arises. Paul states this in Romans 10:17, "So then faith comes by hearing, and hearing by the word of God," dovetailing perfectly with the knowledge mentioned in I John 5:19-20. Saving faith arises from the knowledge God so graciously gives us through His sovereign will. This means that only those whose hearts and minds God opens can believe to salvation. Even the faith that saves is a gift of God!
So on the one hand, there is faith, but on the other is the faith. There is a faith that will believe, yet James describes it as "dead" (James 2:14-26). It is dead, though the person possessing it lives, because all of his labors produce death. They produce death because his faith does not conform to God's will. The faith, given to those ordained to salvation, not only believes but also works in conformity with God's will because it trusts in and relies upon the truth of the salvation message and God's purpose.