That is tied into the leaven of the Pharisees verses the uneavened bread of sincerity
1 Cr 5:8 Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness;
but with the unleavened bread of sincerity and truth.
People can fake a lot of things even fiegn themselves honest, but just because that is true shouldnt change anything for anyone else desiring to be both honest and sincere.
Someone can be plain to anothers conscience too, I believe that.
yes, qualified --- a lot of people (most people) have guilty consciences, or seared consciences, and that makes their thoughts untrustworthy.
a little child in the spirit of yahshua , abiding in union with him, and taught the way he should go, often has the clean and clear fellowship with yahweh, by yahweh's grace, and as HIS WORD says clearly, to perceive and experientially know the TRUTH which is hidden from scholars and lawyers and such as GOD'S WORD says -
to know from GOD what the flesh cannot know or learn.
it is in the spirit that yahweh teaches and communicates with a persons spirit, as written in the NT,
and in the spirit what is learned, may be eventually learned in the mind with words taught by the spirit.
i.e. the hunches, intuition, conscience, and mind cannot perceive spiritual things - spirit perceives spirit, as yahweh says and accomplishes and permits.
this is simpler in experience in yahshua hamashiach , not complicated.