The critique of Christianity is a central theme in R. Kook’s writings; more central than is usually perceived. R. Kook’s anti-Christian sentiment is nourished both by the traditional contempt toward Christianity prevalent in the Kabbalistic literature and by the critique of Christianity raised by modern German philosophers, in particular Hegel and Nietzsche. These bodies of literature are synthesized by R. Kook to produce his own systematic attack on Christianity. At the core of R. Kook’s critique of Christianity stands the notion that the “spirit” of Christianity is, in essence, a negation of Israel and all that it stands for. Christianity, per R. Kook, constantly strives to disrupt the divine plan of salvation by impeding the people of Israel from fulfilling their universal role. While history is seen by R. Kook as constantly marching towards salvation, Christianity is presented as an historical deterioration, even a deviation from the divine plan. The idea that Christianity embodies the negation of Israel lends it special stature in R. Kook’s philosophy. As such, Christianity cannot be elevated and purified like any other phenomenon, but is rather worthy of total rejection. Therefore, even if the Christian religious institution could somehow be refined--as R. Kook suggests in several places--the anti-Israel idea behind the Christian religion should ultimately be blotted out. Essentially, I will argue, R. Kook treats Christianity as something that exceeds the boundaries of his universalism and is worthy of the strongest loathing.