Religion
There is no scholarly consensus over what precisely constitutes a religion. It may be defined as a cultural system of designated behaviors and practices, world views, texts, sanctified places, prophesies, ethics, or organizations, that claims to relate humanity to supernatural, transcendental, or spiritual elements.
Theology
We can no more have exact religious thinking without theology, than exact mensuration and astronomy without mathematics, or exact iron-making without chemistry.
John Hall, p. 580. Quote in Josiah Hotchkiss Gilbert, Dictionary of Burning Words of Brilliant Writers (1895).