Consider carefully what this says. "The flesh" in us is not opposed to us but to the Holy Spirit of God! It is He, not we, who meets and deals with its ways and its lusts. And with what result? "That you may not do the things that you would." I think we have often failed to grasp the importance and significance of that last clause.
Today in the Church as the body of Christ, we still encounter this problem. What "would we do" naturally? We would automatically disregard the will of God and move off on some course of action of our own, dictated to us by our own will according to our own thought and our own feelings. Therefore, the effect of our refusal to come 'out from' the cover of Christ and act 'out of' ourselves, is that the Holy Spirit in us, is free to act for us on our behalf and to do His work in place of us! Free that is, to spontaneously meet and deal with the flesh in us, so that in fact we shall not desire to do what we naturally and normally would do. Instead of going off on a plan and course of our own to do our own thing, we shall find instead that our real joy is in His perfect plan and purpose alone, which is of course His will.