If a church leader would declare his denomination to no longer be trinitarian, my guess is there would be a schism in that group, with "old believers" who would adhere to the previous ways. Not exactly a way to produce unity!
I totally agree. It's a quandary.
Nevertheless, being in a position of responsibility for spiritual guidance is a serious post.
Do you recall Rowan Williams, an archbishop of Canterbury?
Williams, a scholar of the Church Fathers and a historian of Christian spirituality, wrote in 1983 that orthodoxy should be seen "as a tool rather than an end in itself..." It is not something which stands still.
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He subsequently worked with Muslim leaders in England and on the third anniversary of 9/11 spoke, by invitation, at the Al-Azhar University Institute in Cairo on the subject of the Trinity. He stated that the followers of the will of God should not be led into ways of violence.