"A serious house on serious Earth it is." What is "it" referring to in "Church Going"?

Expert Answers
accessteacher eNotes educator| Certified Educator
The reference you have given is the first line of the last stanza, and refers to the importance of the church, both to Larkin and to society at large. Having visited a church and being surprised at the solemnity and power that it still has, this line seems to cement this conclusion with the repetition of the word "serious" to indicate that, whatever our religious beliefs, the church acts as a "serious house on a serious earth." The "it" therefore refers to the church. Note how the stanza continues:
A serious house on a serious earth it is, In whose blent air all our compulsions meet, Are recognised, and robed as destinies. And that much can never be obsolete, Since someone will forever be surprising A hunger in himself to be more serious, And gravitating with it to this ground...
Even though the speaker in this poem dares to mock the church, his actions give him away, as he takes off his bicycle clips with "awkward reverence." Larkin argues that there is something intrinsically important in churches, because they meet a felt need that we have, and when we find that we have "a hunger in [ourselves] to be more serious," churches are the place that we will gravitate to.