Whilst best known for his hymns (Here O Lord, I See Thee; I Lay My Sins on Jesus), I am finding some real spiritual meat in this man's writings. Here is a great quote on what happens when self is replaced with Christ.
"In the place of self the believer gets the Son of God. Christ fills us, occupies us, engrosses us henceforth. He is all to us what self was before. He takes the place of self in everything from first to last, great or small. He is the substitute for self in the matter of our standing before God. As the first thing the Holy Spirit does is to set aside self in the matter of justification and acceptance, so His next is to present to us the Son of God as the true ground of our acceptance. We no longer seek to be justified by self in any sense or on account of anything done to self, on account of ammended self or improved self or mortified self, but solely on account of our Lord Jesus Christ, Who died for us and Who rose again. And in this Son of God, Whom we take as a substitute for self, we find an object worth living for, someone we can carry through every part of our life and into every region of our life." - Horatius Bonar