The plural is a little problematic here. Does it mean that each Sunday they went to more than one church? Or that on successive Sundays they went to different churches? Or is it a colloquial variation for the singular?
Note that to church is not specific as to the number of churches visited over a period of time. While you might expect that people regularly go to a particular church, this meaning is not entailed by the phrase.
If you beleive that the answer to either of the first two questions is yes, and that this is an important distinction to translate, then you might want to incorporate a phrase like different churches or various churches into your translation.