The Christian Writer's Manual of Style has a detailed list of which religious phrases should be capitalized. Here are a couple such examples: Likewise, capitalize Almighty but not God. Do not capitalize Christ or the Holy Spirit. In general, proper nouns (such as names of people) are capitalized. Words used as adjectives or adverbs are not usually capitalized unless they modify a name or title: the blue bird, not the blue birder; once upon a time, not once upon a time; formally dressed, not Formally Dressed. Collective terms are also not capitalized: men and women, parents and children. But words like church and god used as adjectives or adverbs are not capitalized: church bells, to go to church; God knows everything, he is almighty. Capitalizing words makes them act as nouns, which can be confusing because many other words that begin with letters that sound like names are not capitalized: police officer, fireman, priest, minister.