In this video, the late Presbyterian theologian John Gerstner passionately argues for justification by faith alone. He does a beautiful job of explaining this paradox, which the unbelieving simply cannot understand.
Dr. R.C. Sproul was one of Gerstner's seminary students. You may notice the resemblance in style.
Gerstner drives over three dangerous errors on his way to stating the truth . . .
Error: We are saved by Works
Error: We are saved by Faith plus Works
Error: We are saved by Faith minus Works
Truth: We are saved by Faith Alone, from which God-honoring works must (and will) subsequently spring.