data from the Fact2000 study
Shared worship, even more than common community programs, provides the arena for crossing boundaries of historical denominational separation. Forty-five percent of Christian congregations share in ecumenical worship. Far fewer, eight percent of all congregations, share interfaith relationships.
Because of the breadth of participation in this study, comparative responses to denominational, ecumenical and interfaith relationships assume special significance. Christian congregations more frequently worship with ecumenical groups than with other congregations of their own denomination. However, fewer congregations have worshiped with another faith. Congregations appear slightly more likely to work together than to worship together across faith traditions.
Catholic/Orthodox congregations joined with Liberal and Moderate 
Protestants to be the most active participants in ecumenical activities, including the development of local councils of churches, synagogues, mosques, and other religious bodies.
In summary, worship as the corporate act of sharing a sense of God provides the foundational activity among congregations, within themselves and with others. These faith communities also provide a wide array of educational and fellowship events within their congregation, depending on their location and institutional resources. High on their priorities for congregational life are the outreach programs by which congregations express their faith in action.
[Note: Historically Black churches are omitted since they substituted a different question, concerning inter-racial rather than inter-faith events.]
