chains refer to imprisonment, which suggests that Marley is suffering in purgatory Which is a Christian idea, perhaps dickens is warning the audience thats if they don’t change their voracious ways they will end up like Marley in hell.
chains also refers to imprisonment which could refer to the imprisonment of the poor who couldn’t pay their debts due to the poor law.
christian idea of retribution warning his audience that what you do to the poor will come back to you.
“I girded it on my own free will”
“Free will” is a Christian doctrine
original sin- God gave us free will to chose to do good or not but original sin means that we are more likely to do evil and keep money to ourselves but the message is to overcome that.
no man is isolated, each person is responsible for helping each other