Christians, if someone was in a coma for 20 years, would they be living a life without sin? Why or why not?

During those 20 years, yes. Sin is a free and conscious decision to act in a manner contrary to the will of God. One cannot sin while asleep, so one certainly could not sin while in a coma.

It's hard to know what the brain is doing completely in a coma. Recent studies show some people think, dream, and even hear what's going on around them. Scripture makes it clear though, certain thoughts alone are sinful, without a physical action.

That depends. While they may not be sinning while in the coma, in what state were they before entering that coma? If they were lost, then they still are.

No. They would have been sinning before they went into a coma.

No.

A coma the person is still alive being the brain is still functioning while with brain death the person is dead even though their body might be kept alive on machines. It would be sinful to pull the plug (murder) a person in a coma being their brain is still functioning and their body is being kept alive by machines. It would be morally acceptable to pull the plug on a person that was on machines that was brain dead being their spirit has already departed their body.

No it would depend on what the person had done before they went into comma. unless they just left Church and had went to confession and got in an accident i would say they still had sins not forgiven as they did not see this event coming and did not have time to repent. Thanks for the question friend. God bless.

yes they would not be sinning

to sin is to actively do what god said not to do