Am I allowed to say, "too presbyterian"? I fully agree with what the book argues, and agree with most of his arguments, but a couple of issues that bug me. First, rather than going to the simple Bible passages that address the issue directly (which in my opinion would be the most natural and simple approach), McGraw argues for the theological system with great overlap between the chruch triumphant and the church militant, and based on the great overlap concludes, basically, that only those in the church trimphant can be saved, and as a general rule those in the church triumphant will be part of the church militant. Not a bad or unhelpful argument - just uses complex terminology of a theological system to answer what could be answered much more simply. Also devotes a good third of the book to discussing the history behind the Westminster's formulation of this doctrine.
If a reader wants a roundabout route with beautiful scenery along the way, I can heartily recommend this book. But if the reader wants the clearest explanations and Bible verses addressing the titular question... maybe just google it?