But it's not a mercy killing, it's an individual deciding for themself in accordance with a medical expert. It's not society performing a mercy, it's someone telling you how they wish to go. Any idle commentary seems incredibly offensive and presumptive. Anything can be chalked up to a difference of opinion, but having seen people wither away and die, no one's religious objections should ever be relevant. I can't think of anything as disgusting as telling someone dying slowly that their desire is wrong. I just can't.

Being against is only relevant to the person facing the choice. Otherwise you're masquerading religious ideals for actual mercy.