Trying to define "conscience" is about as "easy" as trying to define "soul". Secondly, if conscience was fully "intuitive" then there would be no variations of conscience, so that position is unrealistic, imo. Most Christians and Christian denominations believe they are guided by the Holy Spirit, and yet there are thousands of denominations and billions of people with all sorts of ideas...................
I find the word conscience comes from the Greek word syneidesis: drawn from 'syn' (with) and eidesis (knowledge).
So, co-knowlege or knowledge of oneself. Look at oneself and have a judgement about oneself.
Romans 9:1 mentions one's conscience can bear witness with the person in holy spirit. So, conscience judges.
So, unless damaged, we come equipped with an inborn conscience, that inward sense for right or for wrong.
A conscience can become hardened and calloused like flesh seared by a hot branding iron, becoming unfeeling.
That is why a person can end up with going into total moral collapse.
If one's conscience is Not educated it can thus become an un-safe guide in judgement matters and moral values.
I like this quote from Robert Heinlein (1959) Starship Troopers which says in part:
" you have a cultivated conscience, a most carefully trained one. You were Not born with it......We acquire moral sense.......... through training, experience, and hard sweat of mind."
So, to me a Bible-trained conscience is the best moral compass to guide and direct - Psalms 119:105.