Christians Need the Gospel

In your opinion, why do many Christians view the Gospel as only for unbelievers?
I would guess because we are all slow of heart to see the Gospel clearly. Luther said we have to remind ourselves of it all the time and beat it into our heads continually. I am so deeply self-righteous and self-reliant that it takes effort to remind myself of the grace of God. Take that tendency in all of us and mix it with lack of reading the Bible where we see the Gospel everywhere, and you have all that you need to have a "front door to salvation" view of the Gospel. I also think God is doing this work of making us Gospel centered in a new way in our day. --Mark Lauterbach