We all know how a "promo code" or "coupon code" works.  Enter the proper code, and you get the deal - free shipping, discount, etc.  When it comes to forgiveness of sins and salvation for eternal life, we need a "Promo Code" to get the "deal."  We have nothing to offer except our sinful selves.  Paul tells us that Christ is our "righteousness and sanctification, and redemption."  Only in His Name is there life eternal.