"Christians need to hear the gospel all of their lives because it is the gospel that continues to remind us that our day-to-day acceptance with the Father is not based on what we do for God but upon what Christ did for us in his sinless life and sin-bearing death...
We stand before God today as righteous as we ever will be, even in heaven, because he has clothed us with the righteousness of his Son. Therefore, I don't have to perform to be accepted by God.
Now I am free to obey him and serve him because I am already accepted in Christ (see Rom. 8:1). My driving motivation now is not guilt but gratitude.
Yet even when we understand that our acceptance with God is based on Christ's work, we still naturally tend to drift back into a performance mindset. Consequently, we must continually return to the gospel. To use an expression of the late Jack Miller, we must preach the gospel to ourselves every day."
Read the entire article here (it's a good one).