In the poem I Believe the poet has employed a number of poetic devices to make the poem a great literary piece.

Symbolism
The poem is rich in its use of symbols. ‘Pierce the heavens’, ‘see angels at play’, ‘touch the silky clouds’, ‘swim with the sharks’ and ‘claw into earth’s belley’ — all are symbolic in expressing the speaker’s self-confidence. These symbols are explained well in our summary-analysis post of the poem.

Hyperbole
Hyperbole is an exaggerated statement. The poet has actually overstated her beliefs when she talks of piercing the heavens or touching the clouds. We know one feels that way when the confidence is very high. But this is some exaggeration, no doubt.

Metaphor
A Metaphor is an indirect comparison. In the entire poem Sangma has used a number of metaphors in “the heavens” — comparing life’s highest achievements to heavens, “the stars” — comparing the successful and famous people to stars, “human angels” — comparing great human beings with angels and so on.

Circumlocution
Circumlocution is referring to something in a roundabout way. When the speaker says “here where I dream and breath”, she actually refers to this earth and the society she lives in.

Assonance and consonance
In some places, if we observe well, there are some assonance (repetition of vowel sounds) and consonance (repetition of consonant sounds). For example:

But I firmly believe I’ve to complete

Where I dream and breath.

[You found anything else that I didn’t? Please submit an answer below and help others.]

Anaphora is also used which is a deliberate repetition of a word or phrase made at the beginning of each one of a sequence of sentences, paragraphs or verses. Here the repetition of ‘I Believe’ in every stanza is an example of anaphora.