The Rev Tade Agbesanwa said black majority churches in the Baptist Union of Great Britain were exploring ways to engage with white working class people as he admitted that "white flight" was still a problem in churches today.
"It is a matter of realising who we are," said Agbesanwa, the minister of Custom House Baptist Church in London.
"We are Kingdom people whatever our race. If we are a black majority church in a white majority area, we cannot close our eyes to them."
He said black majority churches were looking at the possibility of partnering with white majority churches and increasing their giving to the Baptist Union's Home Mission appeal, which provides grants to Baptist churches to cover their ministerial stipends and fund local mission activities.
Agbesanwa said the question of why white flight had occurred in churches where black people became the majority was an "uncomfortable" one that Christians needed to answer.
"Can we disciple someone from a different culture?" he said. "When people come to church they come for community. Can black and white communities do life together? It is a challenge for us all, the sooner we talk about it the better."
The questions are among those being addressed at a BUGB conference in London this weekend looking at multicultural church.
Speakers at The Gathering include the head of the BUGB Mission Department Ian Bunce, BMS World Mission Regional Coordinator Chris Andre-Watson, church planter and founder of Urban Expression Stuart Murray Williams, and Diane Blackler, who comes from a white working class background in South East London.
Agbesanwa said, "If blacks and whites in the same church are struggling to stay together, what is the hope that the non-Christian white working class will be attracted to come and stay in a black majority church?"
The Rev Wale Hudson-Roberts, BUGB Racial Justice Advisor and one of the organisers of The Gathering, said the issues were challenging.
"The Gathering will not only be exuberant and varied in its worship but will help us understand and appreciate people from different cultures and classes and allow us to see how we can work closer together for the benefit of God's Kingdom," he said.
The Gathering takes place at Woodgrange Baptist Church in Forest Gate, London from 10:30 to 16:30. For more information visit www.baptist.org.uk/training_events/thegathering_10.html