It's interesting to delve into differing beliefs. An outing to Nossa Senhora do Carmo Church is a wonderful way to better understand a part of the local culture.
You're spoiled for sightseeing choice when visiting Diamantina. Nossa Senhora do Carmo Church is a great place to begin here, but there are many other worthy places to discover. Municipal Market, House of Juscelino Kubitschek, and Cave of Salitre are not far from the house of prayer and and will cap off your day nicely.