Excel,
I think the point the author was trying to say is that suffering is solely because of sin.
While the author may be partially true, he is still far from the whole truth.
This is a question man has attempted to answer, I think, since shortly after the Fall of man. The question "Why?"
Man suffers because of the presence of sin, because sin exists; but not necessarily because the individual himself has personally sinned.
For example:
John 1:1-2- 1 And as Jesus passed by, he saw a man which was blind from his birth. And his disciples asked him, saying, Master, who did sin, this man, or his parents, that he was born blind?
Right away, Jesus' disciples asked the same question Job's friends asked him when he was in torment. And here was Jesus' response:
John 9:3- Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him.
Jesus said that not always is suffering the result of someone's sin. That's Scripture to back up that perspective.
I have not been able to find in the Bible that suffering is consequencial of sin. There are always consequences and punishment to sin, but they are not always suffering.