Rothstein has been called one of Denmark's top researchers in
new religious movements, and has been credited with making them a topic of scholarship. He has called
Lars Hedegaard "an assailant" (), leading to criticism from other free speech advocates. He has been described in a Christian periodical as "uncompromising [and] a wonderful, intelligent man who is both warm, caring and generous with praise for both colleagues and students" An opinion article in another newspaper likewise portrayed him as a hater of religion. == Works ==