I wouldn't say christians compromised their religion because the formation of Christianity included adopting stories and practices from preexisting religions. Aspect of Jesus were taken from Mithras and other deities in nearby regions. Noah's ark and the flood is the same (with small differences) story throughout the world. The Sumerians 5k+ years ago had almost exactly the same story.

Yes they catered to pagans because nature worship was common throughout Europe. The new religion uses traditions of the existing people in order to get the people to practice the new religion. Almost all religions do this.