It isn't biblical. Nowhere in the bible does it say we are saved by faith
alone. Although Luther added the word "alone" to Romans 3:28 controversially so that it read: "thus, we hold, then, that man is justified without the works of the law to do, alone through faith" The word "alone" does not appear in the original Greek text. A little trickery to support his doctrine I suppose.
Jesus never teaches that "faith alone" leads to salvation. He always focuses on works, not as the basis of more rewards, but to obtain salvation. In fact, Jesus even says "by your words you will be justified, and by your words you will be condemned" (Matt 12:37). God's word describes justification by faith and by works. Large portions of the Bible are spent describing condemnation for sins. How could I believe in God but then drastically contradict his teachings (murder, rape, adultery, etc) and still think that I am "once saved always saved" (assuming that I am not repentant)
If we rely on works to save us, then we have become legalistic and not relying on what Christ has done. Yes, in James 2:18 says You say you have faith and I have works; show me your faith without your works and I will show you my faith by my works.
Faith + works