Please bear with me as English is not my first language, :barf:. Forgive my errors of spelling.
Let's try this one more time:
I want to know if E-c-u-m-e-n-i-s-m and I-n-v-i-n-c-i-b-l-e I-g-n-o-r-a-n-c-e are somehow related.
My current understanding is that Ecuмenism is the unity of different religious denominations within Christianity, meaning cooperation between the Catholic Church and other Christian sects. This concept being not too far from Interfaith Pluralism in which there is mutual respect among all world religions. Thus, all religions would be equal before God. No distinction between a Catholic, a Jew, Hindu, Muslim etc.
I understand that Invincible Ignorance opens the possibility of people being saved who are ignorant of the Catholic Faith, through no fault or responsibility of their own. Therefore, a born Jew, Hindu, Muslim, etc. can be saved in their own religions, if they "somehow", on an invincible manner, are members of the Catholic Church.
Could it be that the belief in "Invincible Ignorance" opens the door to Ecuмenism and further more, to Interfaith Pluralism?