Father Jack before going to Africa was a devout Catholic, like the majority of people in Ireland at the time. His job as a missionary, was to go and convert people to Catholicism, however Jack came back from Africa as a devout and associates himself with the paganism ways that they have, using the personal pronouns of "our" and "we".
Within the extra we have our first insight to Jack's life in Africa, first being introduced to how he enters the room the description of "(as if he were intent on some engagement elsewhere)". Friel would've included this intended subconscious action of Jack, to set the scene of his fragmented memory, but his mind set being so fixated of Africa that even back in Ireland, mentally he is in Africa. Jack first shocks Kate and the other sisters with the mentioning of "ancestral spirits" quite an abstract myth in society, but to Jack to mention it would suggest his belief in such things. One significant thing Jack mentions in his first description is "you have dancing" which to the girls we know is their secret desire, their use to escape from their suppressed lives in Ireland and the home they live (trapped) in. Jack's mentioning of dancing, I believe is significant because it evokes the thought and correlation of dance and paganism beliefs within the girls. So to be pagan or some ways apart (The lughnasa festival) is to have the freedom of dance.
The festival of Lughnasa is the closest form of a Paganism ritual to the girls, the description rose gives of the "ritual" of the sacrifice of the cow, is very similar to Jack's description of a typical night or celebration. "We kill a rooster or a young goat... It's very exciting" such care free actions expressed through Jack as he finds it "exciting" and we later learn the reason so they can "offer sacrifice to Obi, our great Goddess of the earth." This description of their actions, show the abstract beliefs the Pagan religion has, and the influence for such extreme measures to connect to a God which contrast completely with the simple 'mass' held within the Catholic religion. This also represents how little of any Catholic beliefs Jack doesn't even have left.
Within the play we see some forms of hostility emerging between Kate and Jack through their differences in beliefs in religion. Kate representing the strong, devout Catholic and Jack representing the free spirited Pagan : this reflects on the conflicts of Catholicism and Paganism in Ireland since the 5th century when British missionaries came over to convert the original pagans to Catholicism, since then it has been the main religion in Ireland but the original pagan beliefs, rituals and festivals still remain among the minorities. When the conversation of Michael pops up, in Jacks terminology Michael is a "love child", on learning this, Jack questions "have you any other love children?". To find have Kate snap back "She certainly has not". As the different religions, to Kate and Catholics a "love child" is against the norms and written rules, as it means it's a baby out of wedlock, but to Jack and the others in Africa, it is the norm as apparently "in Ryanga women are eager to have love children" with the belief of the more you have the more "fortunate your household is thought to be". This example clearly states the conflict created because of religious views, of which Friel is showing the ignorance of people not tolerating others views.
Within the extract, Jack describes how his commissioner refers to him as the "Irish outcast" and always try to get him away so he isn't "going native", here Jack is believing he is apart of them, when to everyone his he is just the outcast. The irony displayed in Jack's character is huge, Jack's job to be a missionary to change peoples religions, however he went to Africa intending to change theirs when it turned out he did go native, his religion and views were changed. When we are first introduced to Jack in the beginning of Act 1, after his introduction to the play we they are then shown insights to the outside world. Obviously Jack's character is one that was able to escape to the outside world, but he brings it back with him and this influence sets the sisters minds to their own knowledge or links to the outside world. The girls thoughts are taken to "Bernie Odonnel" her new husband from "Stockholm", "Curley Mcdaid", significantly Maggie's nostalgic reflection of her memory of dancing. Which all together, shows how Jack's presence back home has brought the outside world, and an aura of paganism- which reflects on freedom and escapism, so it encourages the sisters to think of the outside world, of people with lives they could themselves have.
As we know pre-dating the 5th century Irish Paganism was the main religion in the country, and even today when Catholicism is, minorities still practice the pagan ways. Jack said later on in the play, that "Mother and myself, every Lughnasa would go to the annual ritual", which shows previous on in his life he has a part in paganism, enough to be suppressed by the heavy Catholicism beliefs in his job as a priest, but enough to be brought back to the surface of his mind and believe in the Pagan ways, through his time in Africa. Which could show as a person, how weak Jack is, not to carry on being devout to his religion but to be easily turned to another one. So could the change in Jack's beliefs be the reason why he was sent home as well as his impending death?
Jack's time in Africa describes of everything against Catholic views/beliefs: rituals, sacrifices, love children, Obi Goddess of the Earth, ancestrial spirits, all of which Jack strongly believes in and even home until he dies believes in. We know this because in Michael's speech towards the end, as "he never said Mass again".