What church did Bach write his cantatas for?

Many of these cantatas were written for inclusion in the weekly worship services. In Bach's day, a typical church service could last for 3 or 4 hours. The cantatas were presented usually after the...

Over 300.

church cantata is a vocal composition with an instrumental accompaniment an often containing more than one movement

Yes he did, but they are usually referred to as "Sinfonia" in Bach's time and were not on such as a grand scale as later works. During the Baroque Era, the "Symphony" was in its developmental stages...

Bach did not write classical music. He wrote baroque music.