To me, this verse is talking about the idea that human beings have a sinful side that is rooted in their physical bodies and a side, rooted in their nonphysical souls, that can be more like God. This verse is saying that so long as a person is interested in their physical existence, they cannot truly please God.
I would support this interpretation by looking at the earlier parts of the chapter. Paul is clearly setting up the idea that people's physical nature is bad. You can see this, for example, in 8:5 where he talks about the differences between the bad things that nature wants and the good things that the spirit wants.
This verse uses reference to "the sinful nature." I think some people would interpret this as motivation from the devil, or an evil force. Others would suggest it is the human nature in all of us that seeks the self first.
Christian theology would claim that ultimate happiness and ultimate service comes from he who seeks first to meet the needs of others and then serves one's self. This flies in the face of the contrary belief of today's philosophies that suggest if you can't first make yourself happy, then you aren't going to be able to help others.
Essentially I see this verse as saying, "If you can't get over yourself, you can't make God happy." It is not saying that He won't still accept you. It should be a desire of all Christians to please Him to whom they give credit for creation and salvation.
So with self-control being the theme, and your job must be to do something with this verse, think about those things in your human nature that your selfish nature controls. What do you consume instead of giving time to God... internet? foods? tv? I would imagine you are being asked to consider these as further analysis of this verse.
The 8th verse of the 8th chapter of St.Paul's Epistle to the Romans reads,
and those who are in the flesh cannot please God.
The 'flesh' represents the physical body and its nature. The desires of the flesh especially its desire for sexual gratification, most often by deviant means, are always in conflict with the spiritual aspects of a human being. If bodily desires are not checked and controlled but are given a free rein then this affects the spiritual aspect of a human being. It harms his soul, which is the essence of a human being, for all human beings are mortal and after a person's death his soul goes to heaven or hell depending upon how holy he has lived his live while on earth.
If a person concentrates only on satisfying his bodily and physical lusts he cannot please God. He will be punished after death with his soul going to hell.
King James Bible: So then they that are in the flesh cannot please God (Rom 8:8)
This verse used the word flesh, referring to the human body or the body needs/personal. Sometimes, body would also mean worldly possessions. There have been a lot of bible verses prohibiting people from focusing too much on personal needs or worldly possessions. Remember when Jesus first called his disciples, Andrew and James left their father. And when Matthew was called to be a disciple, he left his job as a tax collector.
If one desires to follow God, he or she should let go of their worldly feelings or worldly possessions. These are things considered to fill the body but not the spirit. So the desires of our flesh, which we easily understand and obey, should be abandoned or forgotten in order for us to follow God with humility and follow God, the source of bread which fills the spirit!