The introduction to the book "Abraham Isaac Kook - The Lights of Penitence, Lights of Holiness, The Moral Principles, Essays, Letters, and Poems", states that Rav Kook was positive toward other religions, and includes direct quotes in support of this. These include:
We must clarify the common elements of all religion, according to the degree of their development, and not be afraid of the customary disdain and deep hostility that lurks in the soul against everything alien (Igrot Harayah, Vol. I, Agudah Lehotzoat Sifre Harayah Kook, Jerusalem, 1943, Letter 194)
The brotherly love of Esau and Jacob [meaning Judaism and Edom], of Isaac and Ishmael [Judaism and Islam], will reise above the confusions fostered by the evil emanating from our creaturely character; it will rise above them and turn them to light and compassion without end (Igrot, Vol. II, Letter 355)
However, his book Orot says something very different as regards idolatry, and especially Christianity. I unfortunately do not have a direct quote, as it was being read to me and translated real-time from Hebrew, so I am working from a combination of memory and my hastily written notes, but I recall quotes that drastically attacked Christianity, calling it "worse than the worst idolatry", "a spiritual blight upon the world", and other similar statements about how it will be destroyed and come to an end. The section of the book also spoke negatively of other religions, but held Christianity especially in contempt.
I struggle to reconcile the above quotes with such statements about Christianity. Let us put aside which of the two views is "correct" for the moment, as that is not my question. Were either set of quotations taken out of context/translated improperly? Was Rav Kook a believer in bringing together most religions but held disdain for Christianity in particular (I will note that it was not mentioned above, though Edom could mean Christianity it is unclear)? Were they written at different times in his life and reflect a changing opinion? Or is there some other way in which these disparate statements may be reconciled?