Ethiopian Orthodox Church is second oldest in Africa, behind Coptic Orthodox Church which is my church. The Ethiopian and the Coptic Orthodox are brothers, and we love very much their saints and they love our saints. There is a Coptic Orthodox church in Alexandria since the 1970s named St. Takla Haymanot Church, which is the famous Ethiopian saint who lots of Coptic people know. The Ethiopian Orthodox got their first bishop after they converted to Christianity from our father St. Athanasius the Apostolic, so the bonds between Ethiopians and Copts are very old. And yes their faith is so strong. Whenever I meet an Ethiopian person I ask them “Are you orthodox?” and they are so happy “Yes! I am Orthodox!” Maybe Ethiopian Catholic is the same, but I never met them. There is a little Catholic church there, and the Italians (Catholics) tried to make it bigger when they came to Ethiopia, but the people are really attached to their Orthodox church, so it didn’t work. But I think it still exists, but without very many members. There are probably more Protestants in Ethiopia than Catholic, because Protestants were popular in places where Orthodoxy was not as strong in the country (with more pagan, more Muslim). So today Protestants are everywhere in the country, but much less in the north (most Orthodox) than in the south (least Orthodox).
My Ethiopian friends love to talk about this, so probably if you meet an Ethiopian and just tell them “I want to know about the church of your country”, they’ll tell you all this (this is what I did, because I found their liturgy online and fell in love with it). Maybe they will know more about the Ethiopian Catholics, too.
