The poem is about faith or conviction going bad, and about the awkward moment of realizing it. The speaker suggests that if something is handled badly, belief doesn't just fade; it dies "wrongly," in a clumsy, painful way. The poem never says what the belief is in, whether a person, a relationship, an idea, or a cause. That openness lets readers fill in their own loss.
The second stanza is the sharpest. Everyone else senses the problem, and the speaker is "the last to know." The isolated "i" on its own line makes the speaker look small and exposed, almost left out of their own story.
The ending turns inward. Bitter monologues, the speech we give ourselves when no one is listening, "seem so redeeming." The word "seem" matters: the speaker half knows this self-justifying anger is no real cure. The mood is quiet, rueful, and a little embarrassed, like someone admitting they have been talking themselves into feeling better.