Answer:
I am a good state, there can be no doubt of itΝΎ But those who are in, entirely are out of it.
A little house full of meat, no door to go in and eat.
Only two backbones and thousands of ribs.
Hard to catch, easy to hold. Can't be seen, unless it's cold.
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?