"A study conducted on 11,000 Evangelical Lutheran Church congregations between 1993 and 2012 claims that racial diversity in churches leads to decline in average attendance."
http://www.christianitydaily.com/articl ... ersity.htm
Despite the findings of the study, its author, Kevin Dougherty, resorts to double-speak in order to soft-pedal the results:
“Racial diversity itself is not a detriment to growth,” said Dougherty. “It is the process of changing the racial composition of a congregation that causes difficulties.”