I saw the question about Caesar, Cicero and how their name used to be pronouncet and I realised that if if the "C" in church used to be pronounced like k's then it would sound much more like how the other germanic languages pronounch church.
There has been a consonant shift in some of the Germanic languages that changed the k-sound to the ch-sound. In Dutch church is kerk, in Danish Kirke, in German Kirche. High German has had another consonant shift that caused the last k to become a ch (like ch in the Scottish Loch). In Frisian, the language the most similar to English on the continent, the word for church is tsjerke. Here you can see the same shift as in English. Frisian and English have had the same shifts that the other germanic languages haven't like this one. So yes originally church was probably something like the Danish or Dutch variant, but this was before the time 'English' was a language.
The english word church is related to the germanic ones, e.g. kirk. Latin tends to use ecclesia, borrowed from the Greek.