To live by grace is to live solely by the merit of Jesus Christ. To live by grace is to base my entire relationship with God, including my acceptance and standing with Him, on my union with Christ.
We fail to see the gospel as the solution to our greatest problem-our guilt, condemnation, and alienation from God. Beyond that, we fail to see it as the basis of our day-to-day acceptance with Him. As a result, many believers live in spiritual poverty.