On the river, when Huck worries about the fact that he is helping Jim escape from slavery he says he feels wicked and that he could feel the hand of God about to take a swing at him. This scares Huck into deciding to turn Jim in to the authorities. The people Huck had known in his young life had used religion to justify slavery. There is an irony here. What is it?

Huck views his surroundings with a practical and logical lens and in the story he is viewed as one that refuses his place in society and heaven. It was established earlier that Huck was not a church-going religious person. He thinks it is useless to pray and he believes prayers won't work for him. However in this scene where he is helping Jim escape from slavery, he fears the hand of God and gets all religious. This is a comment by Twain on religious people who do not act ethically. The alternative way to describe the irony of this scene was that in considering religion Huck was about to do what he regards as appalling putting a man back into slavery, where he would be separated from his family and whipped.