What is the disadvantages of ecumenism?

One disadvantage of ecumenism is that it can lead to the dilution of specific theological beliefs and practices, as different faith traditions may compromise on key doctrines to foster unity. This might result in a loss of distinct identity for individual denominations. Additionally, ecumenism may create tensions among more traditional adherents who feel that their beliefs are being overshadowed or misrepresented in the pursuit of broader interfaith harmony.