On the recommendation of Bo Giertz he began to read books by Carl Olof Rosenius, which made a lasting impression. Rosendal himself used the neo-Thomistic paradigm and resisted all kinds of liberal theology as well as the dialectical theology of Karl Barth.
Following Bo Giertz's suggestion, Rosendal began reading works by Carl Olof Rosenius, whose ideas profoundly influenced him.  Rosendal himself adhered to a neo-Thomist perspective and rejected liberal theology and the dialectical theology of Karl Barth.