In this poem, Blake, as he so often does, presents the reader with one view only to offer the reader a completely opposing alternative. In this poem the view concerns the nature and actions of love. It is the clod of clay on the ground who offers the reader in the first stanza the typical Christian understanding of self-sacrificial love, which is described as follows:
Love seeketh not itself to please,
Nor for itself hath any care,
But for another gives its ease,
And builds a heaven in hell's despair.
This is of course the standard Christian view of love. Yet note how the view of the pebble in the final stanza completely undercuts this view and suggests a much more sinister and contradictory presentation of love:
Love seeketh only Self to please,
To bind another to its delight,
Joy's in another's loss of ease,
And builds a hell in heaven's despite.
This view of love points out the way in which love can actually be a highly dangerous force that can manipulate others and "bind" them to something that makes that love not actually "love" as humans might think of the word but something far more dangerous and malevolent. Blake's poem forces the reader to realise how often love is not innocent and can be used and abused. Perhaps the contrasting values in this poem can best be compared to the states of innocence and experience, which Blake titled his famous collection of poems.
Thank you very much, this has helped me a great deal!