The second group Moody refers as he asks this quuestion, 'Where Art Thou', is to the prodigal - 'to those who have gone back into the world - to the Backslider'.
He makes a statement I find interesting; 'If a man has been born again, and has received the heavenly nature, this world can never satisfy the cravings of his nature'.
'Backsliding' may be more often associated with a total falling away, but with me it was more a series of subtle distractions. I would seriously seek God for a period of time, but then I would always compromise. The compromise would start a slight falling away or a cooling.
It was during these times that the cravings of the old nature were the strongest, and when we are not full of the heavenly nature, we are, to an extent, powerless against the old.
Another statement Moody makes that I find interesting, 'I know that the devil has told you that God won't have anything to do with you, because you have wandered away'. In most cases, that is how I felt. Typical satan style, tempt you to do something you know you shouldn't, then beat you over the head with it when you do.
I think my favorite quote is fitting here. Hudson Taylor said, 'God does not give us overcoming lives. He gives life to those who overcome'. As it was hard to resist the old nature when I was not full of the new, so the converse of that is true - by staying full of the new, the old is easier to resist.