Three short lines, and the whole poem turns on one small swap. Church is usually where a sermon happens, but here the "morning sermon" seems to be a crow calling, and it keeps going "all the way home." The poem never says the speaker is bored by the human sermon or moved by the bird's call. It simply lets the crow take the place of the preacher, or at least outlast him.
The poem reads like a quiet, slightly wry observation. The speaker is walking, and the crow's voice follows, harsh and plain and unpolished. Because the line breaks leave the words hanging, the call feels like it stretches on, as long as the walk itself.
The mood is calm, a little humorous, and gently reverent toward the natural world. The poem suggests that something worth listening to may be found outdoors, in an ordinary sound, rather than inside the building. It doesn't push that idea. It just lets the crow keep calling.