In "Mending Wall," by Robert Frost, two men walk on either side of a stone wall each spring in order to repair the damage (in the form of gaps and fallen stones caused by animals, hunters, and nature) done over the year. In truth, the neighbors do not actually need the wall.
There where it is we do not need the wall:
He is all pine and I am apple orchard.
My apple trees will never get across
And eat the cones under his pines.
Nothing on one side of the wall is going to encroach on the other side; therefore, the wall is not a physical necessity. Instead it seems to be the only point of relationship between these two men.
The younger man considers himself to be a superior thinker, repeating his belief that "something there is that doesn't love a wall." He makes fun of his older neighbor who has his own saying, which he repeats several times: "'Good fences make good neighbors.'" The younger man believes he is more enlightened than his "old-stone savage armed" neighbor who "moves in darkness." Each spring, however, it is the younger neighbor who seeks out the older man to repair the wall.
The speaker of the poem acts rather superior when he says:
Before I built a wall I'd ask to know
What I was walling in or walling out,
And to whom I was like to give offence.
Yet he does not engage in any self-examination or contemplation about his yearly effort to repair the wall. In practice, the younger man is no more enlightened that the older man. They each rather cling to the habit and presence of the wall.
Perhaps maintaining this connection is for the purpose of "the redemption and renewal of human relationships." Each man has his own reasons for wanting to keep the wall in good repair, though neither of them seems able to articulate his need for the wall. The wall seems to be their one point of contact; to that extent, the wall is useful for the the maintenance and renewal of their relationship. Redemption, the saving of one from sin or evil, is a little more difficult to see in this poem. It does not seem likely that mending and maintaining this wall brings salvation to either man.