The best way, IMHO, to advance interest in theology is to study Scripture within the context of Scripture (not start with a theological concept or book and then look to Scripture for its justification). Instead of advocating a study of the Doctrines of Grace in John, why not start with John. Work through the gospel and epistles and allow Scripture to bring out the theology within its own context?
I say this for two reasons. First, Lawson’s view is not authoritative - he may be wrong on some point while Scripture is not wrong. Second, it is much better to derive theology from Scripture than to explore Scripture through a theological perspective (even if it winds up that the theology you are considering is correct). It is, IMHO, disgraceful that churches rely so heavily on study guides to give them an interpretation of Scripture when we all have access to Bibles. Start with the Bible and then use tools. Just a suggestion.
This is the approach of David Jeremiah and Erwin Lutzer whom have stayed out of the CAL/ARMIN Debate and maybe for good reason.