This book was helpful practically and would especially be helpful for church leaders thinking about how to diversify or simplify their church's strategy of evangelism, as well as encourage those involved in evangelism by pointing out a simple strategy designed to move people along an Engels scale of faith.
A couple of the book's limitations: -Lawrence makes good points but probably tries to hang them on the wrong Bible verses too often- this results in his stretching of Bible passages to make his point, like the idea of having to plough the rocky soil with prayer to convert it to good soil -written in the nineties, it is suitably cringy in plenty of places, with very Christianised and charismatic language -it often feels like his definitions of things like evangelism, sin etc are not really the ones the Bible gives -often claims he is redefining evangelism in light of conservative bigots but his book is actually full of straw-men, especially in the first half
These limitations do hinder the books utility; once you get past them, it can be thought-provoking.