From Jeanne Murray Walker's essay "On Poets and Poetry":

I would add another category of bad poems: those that are not marked by a struggle with the medium of language. They are English gussied up to look like poetry. Some such poems are written in order to argue some dogma: Marxism, Christianity, the superiority of a breath freshener. There is poetry and then there is dogma. Both have their place. But they have very different personalities. If I start a poem with dogma rather than a metaphor, say, or a dramatic voice, it usually goes bad, even if I try to fix it using a lot of metaphor. I don't mean that any poem with an idea in it is bad. Not at all. I mean that a poem seems to include its own fossil record of how it was conceived. I find that I can't cheat on this score. If I start with an idea, if I don't have to struggle to get there, the poem is likely to sound idea-driven and polemical. . . .  

Then what is the relationship between poetry and truth? I think the point of all the arts, including poetry, is to tell the truth about what it is to be human. . . .  

. . . It's wrong to read a poem as if it were a list of propositions. And it's wrong to ask poetry to supply us with such a list, since poetry, like other arts, represents rather than argues. Beyond this, I am very skeptical toward anyone who tells me that he knows some piece of art or another doesn't conform to the truth and therefore should be banished. Human experience is very broad, and truth is wider than the universe. . . .  

. . . The ultimate purpose of our creation is to know and love God, but there are a practically infinite number of interesting things going on in the universe, and it seems to me that they are all fair game for writers. I believe that the art for art's sake movement, for example, which led to confessional poetry, is heartbreakingly and awfully mistaken. Art is wonderful, but it cannot save us and it cannot be the whole point. And yet I do not believe that the point of art is to spread the gospel either. Take a look at the variety of what God has created: giraffes, hedgehogs, the dawn, the mind-boggling world of a cell, the Milky Way. He is not didactic. He has a sense of humor. And He must be fascinated by His whole creation.