Does the poem "To The Reader" use figurative lanuage?

In short, yes, it uses lot of figurative language. A few examples:

There is a simile in the first stanza: "we feed our pleasant remorse

As beggars nourish their vermin."

The next line personifies qualities by giving them human characteristics: "Our sins are obstinate, our repentance is faint;"

Overall, the whole poem dabbles in metaphor, talking about our sinfulness as being controlled by devils, our sins as animals, etc. It's chock full of figurative language.