What groundwork did Paul lay in Romans 1–7 before introducing the Holy Spirit in Romans 8?
In Romans 1–7, Paul laid the groundwork by showing how humanity ended up in sin and under condemnation, and how Christ died so believers might be justified and forgiven. Chapter 7 then presents the dilemma of overcoming the old Adam, setting the stage for Romans 8's answer: the indwelling Holy Spirit.
Les explains that in those first seven chapters Paul lays all the groundwork of how we ended up in sin and under condemnation, and how Christ died that we might be justified from all that and forgiven. Then Paul comes through chapter 7 with the dilemma of how to overcome the old Adam and keep it in defeat. The answer is Romans chapter 8: the Holy Spirit, the indwelling Spirit that now becomes our Law. Within that discussion, the Law being spoken of is the Mosaic Law, the Ten Commandments, which was weak through the flesh.