1 is bad because people are punished for something that isn't their fault; 2 would blatantly contradict what Christians think is good.

Hmmmm. Here's a third option; the punishment for a sin committed in ignorance is a lot lighter than the punishment for a sin committed deliberately. "A lot lighter" implies neither infinite nor eternal; merely a firm hint that that is not the way to go about things.

In this case, letting people know what the rules are will save them a lot of trouble (and trial-and-error) along the way.