This commentary on John is a "theological" interpretation of John's Gospel that is heavily influenced by Calvin's commentary and by Calvinism. It is easy enough to follow and provocative. If you are a sacramentalist, Ridderbos will annoy you beyond imagination (he hardly EVER sees allusions to the sacraments) although he always does so intelligently. My impression is that Ridderbos is a better Pauline scholar than a Johannine one, although there can be no doubt this is an important work. If you want an unorthodox commentary that is not intimidated by any "modern" interpretation or ecclesiastical interpretation of John this is a good buy.