There is a church near to railway station thats why its called church gate
aapko itna bhi nahi pata bhabhi ji

This not not the only thing. There is no monkey in Bandra and no darkness in Andheri. A lot of dark people in Goregaon and hanging garden does not hang (just joking)

There is a Roman Catholic Church that large Brick building which you see while coming from Nariman point to Churchgate , I think you need to catch 123 bus from Churchgate to RC Church I do not remember number correctly as I was there many years back.

Now the church it is not visible from Church gate station because metro cinema and other buildings such as western railway office is in between but when station was named the Church was bang opposite .

Churchgate (Marathi: ) is an area in downtown South Mumbai (formerly Bombay). The station gets its name from Church Gate street (now Veer Nariman Road) which lines on the immediate south of the station. During the eighteenth and up to the mid 19th century, Bombay was a walled city. The city walls had three gates, and Church Gate, named after St. Thomas Cathedral, Mumbai was one of the gates. The gate on situated near the present day location of Flora Fountain. In the mid nineteenth century, the city walls were torn down to aid in the expansion program.