M. Charles Bell’s book Calvin and Scottish Theology: The Doctrine of Assurance (Edinburgh: The Handsel Press, 1985) is one book I have been working through recently. It is ambitious in scope, in that it aims to give a tour of Scottish theology from John Knox to John MacLeod Campbell (against the background of Calvin) focusing on the issue of assurance and related topics. A lot of neglected theologians are covered in the book and Durham gets a significant place in the book which is good in that it gives me plenty to work on in my thesis!
Nevertheless, this is not a book that is recommended bedside (or any other kind of) reading. The author, in my opinion, misreads Calvin and then attempts to set him against 17th C Scottish theology. Incidentally, I think he has also misread Scottish theology to an extent (or at least cast it in as bad a light as possible). 17th C Scottish theology in this book is judged as being simply very bad theology. The book then is, in my view, historically and theologically suspect. Having said that the book is not all bad and if you have the ability to sift the (small amount of) wheat from the (large heaps of) chaff there are a number of interesting points made. One of the best is in Bell’s discussion of Ebenezer Erskine on the gospel offer. Here are a couple of good quotes.
[Ebenezer Erskine] teaches that only the elect shall savingly close with Christ in the covenant since ‘all saving influences’ of God’s Spirit are peculiar to the elect. (Works, Vol 1, p4,48)… such teaching is, for many, an obstacle to their coming to Christ… [Erskine’s] usual response is to assert that we have nothing to do with election since this is hidden in God’s secret will. (3:100,125,278,431). We should interest ourselves in God’s will as revealed in his promises… The promises, then, are a door by which faith may enter into the new covenant (3:261), and by them ‘the reprobate have as good a revealed warrant for believing as the elect have’ (1:387). In reference to God and his promises, Erskine states that we should view the Scripture’s promises as a genuine revelation of God’s thoughts and feelings towards us, ‘for unbelief is ready to suggest that he says one thing and thinks another’ (2:146). With this statement, Erskine brings us to the heart of the matter, and that is the issue of one’s doctrine of God.
p162
Here Bell notes that Erskine believes and teaches election (for Bell that is a bad thing). This raises questions in the minds of the hearers of the gospel – am I elect? How does Erskine respond? The same way Durham does, by directing us away from the hidden things to the revealed things. And when we turn to the revealed things we see all, elect and reprobate, have the same warrant to come to Christ. Interestingly, Erskine, just as Durham does, moves beyond this to assert the sincerity of God in the gospel offer. Bell’s comment regarding those who have an issue with a genuine gospel offer is to the point, “the issue is one’s doctrine of God”. If we are unable to maintain the sincerity or well meant nature of the free offer of the gospel then something has gone wrong with our doctrine of God. Interestingly, D.B. Williams PhD thesis, Herman Hoeksema’s theological method (University of Wales, Lampeter, 2000) notes that Hoeksema’s views on “common grace and the well meant offer could not have been other than they were” given his theological method. Therefore those who seek to evaluate Hoeksema on the free offer and common grace directly “have entered the Hoeksema edifice at the back door”. It is his theological method that really drives his particular views. So to get a handle on denials of the free offer we need to step back from the direct issues and consider theological method and the doctrine of God as well. That is an important point. (I haven’t read Williams’ thesis yet – the point I quoted here was from his abstract).
Erskine… urges us to realise that God’s heart as revealed in Jesus Christ is full of grace and love for lost sinners. He pleads that we ‘not think that a God of truth dissembles with you, when he makes offer of his unspeakable gift, or that he offers you a thing he has no mind to give.’ (1:220).
p163
Now Ebenezer Erskine was a thoroughly orthodox Scottish ‘Calvinist’ – he clearly espouses a definite atonement. Yet he 
also clearly maintains that the free offer is well meant. God does not “dissemble” with us in the free offer. That is, he does not give a false or misleading appearance; he does not put on an appearance of sincerity or merely feign an offer of salvation. The free offer is genuine, well meant and is not an offer of a thing “he has no mind to give”.
John J. Murray, coming at this from an orthodox angle as opposed to Bell’s unorthodoxy, makes a similar point commenting on Thomas Boston (a close friend of Erskine): “Boston shows us how to hold the doctrines of election and particular redemption together with the preaching of the full and free offer of Christ to all men. Holding the most exalted Reformed orthodoxy we can invite sinners to the Lord Jesus… The love that flows from the heart of God to sinners as we see in the parable of the prodigal son is free and unconditional. Are we guilty of hedging about the love of God so as to protect it? … it is … revealed as a love that desires the salvation of all men. The offer of Christ and his benefits is a bona fide offer. We as ambassadors for Christ beseech sinners in God’s stead.” (‘The Marrow Controversy – Thomas Boston and the Free Offer’, Preaching and Revival, The Westminster Conference, 1984).
Marrow theology is reformed theology at its best (and despite some different nuances, e.g. on the covenant of redemption, it is essentially the same theology as Durham). Read Thomas Boston, Ralph Erskine and Ebenezer Erskine – they will do your soul good!
James Durham Thesis 