Lord of the flies could be a reflection by the adult world who believe children are innocent but when faced with the same adult like situation they seemed capable of commiting acts of violence more severe than adults. This could be because they lacked experience of life that made them fearless as they were not aware of the consequences.
Simon represents the good that exists in each one of us , Ralph the grey areas that we exist in and jack and Roger the black or evil areas of our life. Each one of this exists within us but the only differece is that they vary in the extent.
The virgin forest represents children without experience but if this gaining of life's experience is not nutured and guided well then the situation one faces is what is contained in the book.
The writer gives us a subtle warning that we should not underestimate any situation but approach each situation well thought out.
Wordsworth's 'The child is the father of the man' is apt when we see that a child shows the potential of evil .