The speaker is sitting in a church pew, but their attention isn't on the service. Next to them is someone whose confidence seems to fill the whole pew, a calm faith the speaker can sense but doesn't share. Instead, their eye drifts to "the wing." The word is ambiguous. It could be a bird's wing, an angel in a window or carving, or even the side section of the church building. The poem doesn't say, and that openness is part of its charm.
The title, "Participant observer," helps explain the distance. The speaker is present, yet watching from slightly outside. The last lines, "a voyage in good company / and me," turn on that small word "and." The others travel together, while the speaker is tacked on at the end, included but apart. The mood is quiet and gently wry. There's no anger at belief, just a thoughtful, slightly lonely awareness of being a visitor among people who feel at home.