But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
Note 25 at Ro 8:11: This verse is speaking of more than just the quickening of our bodies at the second return of Christ, although that is included. In Ro 8:10, Paul spoke of the body being dead because of sin, but the Spirit being life because of righteousness. This is speaking of the current situation we face in this life.
Our flesh (see note 3 at Ro 7:18) has been rendered incapable of serving God correctly because of the effect sin has had on us, but our situation isn't hopeless. God has given us His Spirit, and we can overcome this deficit by letting Him live through us (Ga 2:20). Here in Ro 8:11, Paul was commenting on this quickening power of the Holy Spirit for this life as well as the ultimate victory when our physical bodies will be resurrected.