I believe the writer wants us to know that if we are selfish and vile toward one another, we will always have a storm in our lives. The story explains that the Giant had a continuous winter storm in his garden because he wouldn’t allow the children to play there; this showed us his selfishness. The writer also revealed that the Giant kept company with a Cornish ogre (a giantic hideous monster that ate humans) thus, revealing how vile the Giant was.

The Giant was moved with compassion when he saw a little boy struggling to get into a tree. The writer later conveyed that the little boy represented Jesus and because the Giant "blessed" the little boy and other children by letting them play in his garden, God blessed him by allowing the Giant into His Paradise.

My opinion is that the writer is trying to inform us that if we share and treat others with compassion, one day, God will reward us by opening his Kingdom and allowing us to "play" there, forever.