Harvard Divinity School professor Stephanie Paulsell tells about worshipping at Harvard:
Yes, this is syncretism, celebrated at one of our most prestigious mainline seminaries and lauded in the mainline Christian Century. This is where liberal theology is these days. But note the difference. A few years ago, what was once the multi-denominational and then became the multi-faith worship service would mush all of the different religions in a worship service that would be recognizable to none of them. Now, though, the distinct worship services of the distinct religions are carried out, but everyone participates in them and honors them all equally.
This is the difference between ecumenism and polytheism.