Author Jerry Bridges in his book, The Discipline of Grace, explains this concept: “To preach the gospel to yourself, then, means that you continually face up to your own sinfulness and then flee to Jesus through faith in His shed blood and righteous life.”
Bridges writes that the Gospel is something to be preached to Christians as well as unbelievers.
As for the benefit of doing so, Milton Vincent says it well:
“Over the course of time, preaching the gospel to myself every day has made
more of a difference in my life than any other discipline I have ever practiced.
I find myself sinning less, but just as importantly, I find myself recovering my
footing more quickly after sinning, due to the immediate comfort found in the
gospel. I have also found that when I am absorbed in the gospel, everything else
I am supposed to be toward God and others seems to flow out of me more naturally
and passionately. Doing right is not always easy, but it is never more easy than
when one is breathing deeply the atmosphere of the gospel.”
For the complete series from Girltalk, click here. (This is not just for girls, by the way.)
And if you are at all unsure what exactly the "Gospel" is, please click here, for a presentation of the most important message you will ever hear.