"Q: Why is it so hard to lead a self-denying, humble life?
A: Because professed Christians are not dead to the world."
E.G.W.
"In Romans 6:11, the word “reckon” (account as, in the sense of 
book keeping) is twisted by the New Theology to say that we are to consider the “old man” to be dead, regardless of how much he is jumping around and ruling our behavior. It is based on the idea that once a person is converted, they can never backslide–“once saved, only saved.”
It is the idea that the “old man” can only die once, and can never come to life again. The word of God is clear– “he that doeth righteousness is righteous, even as He is righteous. He that committeth sin is of the devil; for the devil sinneth from the beginning.” 1 John 3:8-10."
ChristopherFischer