Alongside this, it had the biggest first-week sales of any release on Tooth & Nail Records. Define the Great Line was certified gold by the Recording Industry Association of America (RIAA) in November 2006 for selling 500,000 copies.
Define the Great Line debuted at number two on the Billboard 200 charts, selling over 98,000 copies in its first week. It became the highest-charting Christian release since You Light Up My Life: Inspirational Songs by LeAnn Rimes reached the top spot in 1997.