Question: God tells His people to avoid imitating pagan practices. Yet I see that most professing Christians describe their denominations, and the buildings in which they worship, as "churches." Since "Circe" (Greek Kirke, meaning "falcon") is the name of a Greek goddess, how can it be associated with Christian worship?
Answer: Who was Circe? In various accounts in Greek mythology, she was "a sorceress, the daughter of Helios, the sun god, and the ocean nymph Perse" (Encyclopaedia Britannica, "Circe"). Made noteworthy mostly by her appearance in Homer's The Odyssey, Circe is otherwise a relatively minor mythological figure.
Circe's association with the "sun god" has led some few people to connect the English word "church" and its antecedents with her name as one more example of how pagan sun worship has infiltrated "mainstream Christianity". But other than the coincidence of spelling between Circe’s name and the antecedents of "church" at various times, no evidence exists to prove a connection. This is not like the well- documented connection between the Anglo-Saxon fertility goddess Oestre (the religious equivalent of the Middle Eastern goddesses Astarte and Ishtar) and the name Easter. There one can trace the historical and at least some of the linguistic connections. There are none between "Circe" and "church."
It is true that "church" can be traced to an Old English word that is sometimes spelled circe (in some historical sources it is spelled cirice). Any of the better dictionaries having etymological references will give this information in whole or in part. However, some people then make a leap which the dictionaries do not: they connect the Old English cir(i)ce with the Circe or Kirkē of classical mythology.
Using several references on the subject (The Oxford Unabridged Dictionary, The American Heritage Dictionary, and The Merriam-Webster's Collegiate Dictionary), we can trace the development of "church" and its parallels in other languages. The ultimate source is probably the early Christian Greek phrase kyri(a)kon (doma), "the Lord's (house)". The Greek kyriakon (literally "of the Lord") was used of houses of Christian worship since about 300ad, especially in the East, though it was less common in this sense than ekklesia or basilike. This word is an example of direct Greek-to-Germanic borrowing of Christian words by the Goths; it was probably used by West Germanic people in their pre-Christian period. The word was also borrowed into Slavic from Germanic (cf. Old Slavic criky, Russian cerkov). Romance and Celtic languages use variants of the Latin form ecclesia, found in the Latin Vulgate version.
Since English is a Germanic language, it is not surprising that kyriakon carried over directly from Greek via Germanic. It was used in English before 900ad. In Old English it appears as cir(i)ce; in Middle English, as chir(i)che; in Modern English, as church (there was a parallel mutation of vowels in what became our word bury). Thus church is akin to the Dutch kerk, the German Kirche, the Old Norse kirkja, and the Scottisk kirk. All these came from Greek via Germanic. But these words (like their original Greek source) meant the place of assembly, rather than the assembly itself as the biblical ekklesia does. William Tyndale's New Testament uses "robbers of churches" only in Acts 19:37, and then only in reference to those who commit sacrilege against pagan temples (the Greek word translated "robbers of churches" is the plural of hierosulos). Consistently, he translates ekklesia as "congregation," regardless of context.
Given how kyriakon developed into church and its parallels in other languages, it was inevitable that some coincidence with Circe or Kirke would arise in terms of spelling. However, it takes more than coincidence to derive the word "church" from a minor figure in Greek mythology, whether connected to a major mythological sun god or not. Such a hypothetical connection is without concrete support, and goes against other lines of real evidence. God nowhere commands the use of one particular language as sacred for His people today, nor does He forbid the use of the "vernacular" for expressing concepts such as ekklesia, kyriakon, or even the names of God Himself.