Clough borrows the Psalms' famous verdict, "The fool hath said in his heart, There is no God," and turns it into a cross-examination. He doesn't ask whether God exists. He asks who is saying so, and why. For most of the poem the answer is uncomfortably human: people believe or disbelieve according to what suits them.
The first four stanzas parade a series of unbelievers, and each one's atheism is self-serving. The "wicked" man is relieved because he'd rather not guess "what He might have done with us", which suggests he expects punishment. The youngster complains that God surely didn't mean a man "Always to be a baby", which sounds like impatience with being told how to behave. That is an inference, but the tone supports it. The tradesman worries that God might "take it ill" if he makes "a little money", and the word "little" is a nicely shameless understatement. The best joke belongs to the rich man, who dismisses the question yet says he and his family are fortunate, "thank somebody". He denies God and still reaches for gratitude by reflex.
The form keeps all this light. The quatrains are ballad-like, with longer and shorter lines alternating and rhymes falling on the second and fourth lines. Many of the rhymes are feminine and slightly comic: "blessing" with "guessing", "funny" with "money", "little" with "victual". The bounce is almost nursery-rhyme, and it deflates a grand subject. This lets Clough say risky things in the manner of a gentle satirist rather than a prosecutor.
The verbs also change as the poem goes on. It opens with the archaic, pulpit-sounding "saith", then moves to "thinks", then to the unbelievers who "think there is none" without much effort. Disbelief shrinks from a public declaration to a private mood. The fifth stanza completes the slide with people who "scarce so much as doubt it" and who drift into atheism "when they are well, / And do not think about it." On this view, disbelief is often just what comfort feels like.
Then comes the turn at "But". Clough's believers are those who live "beneath / The shadow of the steeple". A shadow can shelter or darken, and he doesn't say which. The list that follows slides into anticlimax: "The parson and the parson's wife, / And mostly married people." That "mostly" is a shrug that makes the whole catalogue gently absurd. Young lovers are "so thankful for illusion", and the word "illusion" is the sharpest in the poem, since it quietly questions what they are being thankful for. The guilty are caught in "what the world / Calls guilt", a phrase that lets Clough keep his distance from the world's moral labels. Each group believes because of a situation: habit, love, shame.
The last stanza makes this explicit. Belief arrives when "age, / Disease, or sorrows strike him", and "strike" is a physical, sudden verb. The man doesn't conclude that there is a God. He "inclines to think" so, a phrase that describes leaning rather than knowing. Then comes the hedge, "Or something very like Him." The rhyme of "strike him" with "like Him" turns on the capital H, which only a reader can see. Even the pronoun separates the human sufferer from the divine, and the vagueness of "something very like" makes the faith that results sound thin and improvised.
What makes the poem significant is its refusal to take a side. Clough never says God does not exist, and he never says the believers are right. What he exposes is how often our convictions on the biggest question follow our circumstances: fear, profit, ease, love, grief. This unsettles both camps. A believer has to wonder whether faith is just a response to need, and a sceptic has to wonder whether doubt is just a convenience of good health and a full purse. For Victorian readers anxious about religion, that was a sharp question. It still works today, because it is asked with a smile and no one is allowed to feel superior.