The Pope states that ecumenism is not optional:
Pointing out that “ecumenism is not something optional,” he said it aims “to develop a common and consistent witness that promotes true justice and support for the weakest through responses that are concrete, appropriate and effective”.
Go here to read the rest. Ecumenism not optional? Try ecumenism is not possible. All Christians haven’t belonged to one family since shortly after the Crucifixion. The early Church was beset by heresies, and thus it has remained throughout more than twenty centuries. Other recent popes have been infatuated with ecumenism, a truly bad idea arising in the last century. It is, at best, a game of pretend where serious divisions in dogma and theology are papered over, at worst it is a movement based upon mendacity. Pius XI summed up true ecumenism for Catholics:
“There is but one way in which the unity of Christians may be fostered, and that is by furthering the return to the one true Church of Christ of those who are separated from it; for far from that one true Church they have in the past fallen away. The one Church of Christ is visible to all, and will remain, according to the will of its Author, exactly the same as He instituted it.”
None of this does not mean that the Church should not strive for good relations with other Christian denominations, working together on charitable projects, or allying to resist government encroachments on religious liberty, for example. But always, the Church must remain true to herself and to Truth.