The poem
'The child is father to the man.' How can he be? The words are wild. Suck any sense from that who can: 'The child is father to the man.' No; what the poet did write ran, 'The man is father to the child.' 'The child is father to the man!' How can he be? The words are wild.

Remembering this one from school, I don't recall our analysis of it, but to me now, it has come to represent the role exchanges that are slowly taking place as my own Father ages. At 93, he does rather well, but I truly have become "father to the man".It is a wild transition! Strike a cord with anyone?
Given Hopkins personal history and reason for resuming the writing of poetry, it would seem plausible that the meaning beneath the script is that Christ is the father of all men (people). Christ came as a child/baby and gave life to us all through his ultimate personal sacrifice.
This poem is about the poet's questioning of Wordsworth's poem.