The speakers in the poems of the "Songs of Innocence" are sweet and childlike. In most cases, they are children. They are different from the poet, Blake, who has a level of experience of the world's evils that the children speaking do not.
The speakers of the various innocence poems have been taught about Jesus as a sweet and gentle shepherd who will take care of them. They have been told that if they are good and faithful, they will be protected and rewarded: in other words, that they live in a just world.
The speakers use the simple words of a child. An example would be in the opening of "The Shepherd," which is made up almost entirely of words of one syllable, with the childlike repetition of the word "sweet":
How sweet is the Shepherd's sweet lot
In "The Echoing Green," the speaker uses the word "our" to describe children at play, revealing that it is an innocent child telling the story of happy times in a pastoral English village, where children have the opportunity to play and experience nature. Again, the cadences and rhymes are sing-song, like a nursery rhyme, and the word are very simple:
The merry bells ring
To welcome the Spring
The childlike speaker of "The Lamb" has an uncomplicated understanding of Christianity as all gentleness and kindness, with Jesus pictured as lovingly protecting the children.
By the time we get to "The Chimney Sweep," told from the point of view of a child who is an oppressed chimney sweep, Blake is starting to complicate this picture. The poem plays on the slippage between the trust the little boy speaker has that God will take care of him if he is good, and the reader's knowledge that the world doesn't work that way.
In "Songs of Experience," Blake adds the dark shadings of reality to the pictures painted in these poems of innocence.