Summary
This quote suggests that underneath the surface adherence to Christianity, there often lies remnants of older, more primitive beliefs and instincts. It implies that the purity and true essence of Christianity may become corrupted or diluted by the influence of pre-Christian beliefs and customs. In other words, it proposes that the person claiming to be a devout Christian may still exhibit qualities or engage in behaviors that contradict the teachings of their faith, thereby revealing their true nature as being less spiritual and more influenced by their more innate, "pagan" tendencies.