Well, in the bible "2. Corinthian 6:14-15" clearly says "Do not yoked with unbelievers" (Not pray with Non-Christians), during in the qural "surah 109" clearly says our faith is not the same, so Ecumenism makes the opposite when representives of this ideology say "all people would have the same God".

Atheists who call themself believer support Ecumenism, so it's an attack of teachings which believers have to follow and this pic shows some leaders of Germany who seems to have no problem to trade teachings which they to pretend to represent.