Louis Berkhof 
Recent Trends in Theology [EPUB ebook] 

Religion and theology are very closely related, but are by no means identical. Religion is a relationship between man and his God, while theology is the knowledge which man has of God. The question has sometimes been raised, whether religion gave birth to theology, or theology called forth religion. A careful consideration of the relation between the two soon leads to the conclusion that neither one of these alternatives is acceptable. They are both effects of the same cause, namely, of the revelation of God respecting His own Being, and His handiwork. True religion and real theology are both rooted in the divine revelation which God has been pleased to give unto man, and which is embodied in His inspired Word. Apart from that Word there is no genuine religion, nor any theology that is properly so called.
Cross Reach Publications