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.
Bo Giertz recommended Carl Olof Rosenius's writings, which had a lasting impact on Rosendal. Rosendal embraced a neo-Thomistic approach and opposed liberal theology and Karl Barth's dialectical theology.