There is no more important moral issue for our society than abortion, but it would be unfortunate to dismiss progress toward Christian unity. Compromise of doctrine should only occur when doctrine is shown to be insufficient through revelation or inspiration. In the interim the point of dialog between Christian denominations is to strengthen our community and lead to better understanding of Biblical Truth.
As an evangelic and Calvinist I have little use for the ecumenical movement. Phase one seemed to be to merge our doctrines and return to a pre reformation position and even include those that deny the nicene creed like univeralists and unitarians , phase 2 , now in effect in our area includes those that deny Christ in the mix like Hindus and Muslims with whom we absolutely no fellowship .
I have no issue with sharing actions on major social issues with others that affirm Christ. But you will find few Calvinists or evangelicals that will return to Catholic doctrines or share "worship" with those that have other gods .