Spiritual discernment comes about through Spiritual unfoldment, allowing us to understand what 'spirit forces' are at work in us, at work in the course of our daily lives, and at work in the lives of those around us. Spiritual discernment is not physical discernment nor is it mind reading. Spiritual discernment cannot be 'seen' or 'felt', it can only be understood from our own personal experiences with spirit, spirit phenomena, and with Spirit and Spiritual revelations. Reading 1John 4:1, "Believe not every spirit, but 'try' the spirits whether they are of God."
Spiritual discernment is 'experienced based knowledge' whereby you know whether the spirit before you is of God, or of error: even if some other spirit of error is operating through the person before you. Spiritual discernment is the distinguishing between spirits, whether they be of God or not, and to do so you 'try' them.
The 'acid test' of Spiritual discernment is - "is what is being shown or communicated Spiritual, or physical? - is it about heaven, Jesus and God, or is it about this physical world and the things of this world; reading 1Corinthians 2:13, "These things we also speak, not in the words which men's wisdom teaches, but which the holy Spirit teaches, comparing spiritual things with spiritual. (But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are SPIRITUALL DISCERNED.)"
Spiritual discernment allows us to understand, from our own personal experiences, the motivations of our self, as well as the motivations of those around us: whether the Spirit of God is at work, or is it the spirit of perdition, a spirit of this world. "Every one skilled in the word of righteousness, have their (spiritual) senses exercised to discern good and evil." Think of spiritual discernment as looking at things from God's point of view - RIGHTEOUSNESS!
Spiritual discernment is to help us navigate through the evil of each day, developing the perfect man, the righteous man. "Take no thought for the morrow, for the morrow shall take thought for the things of itself: sufficient unto the day is the evil thereof." (Matthew 6:34) "Be not conformed to this world - but be ye transformed by the renewing of your MIND, that ye may 'prove' what is that good, acceptable and perfect will of God. Put on the new man which is renewed in knowledge after the image of Him that created him." (Rm 12:2 ; Col 3:10)
Satan is the ruler of this world. He lives through and directs all beings within his creation using the soul. Through the soul, Satan causes all things and all beings to revolve ... to go through cycles, just as if they were attached to a machine that turns them round and round on the Wheel, where our attention is constantly being bounced around from thinking - to - feeling, from feeling to memories, from memories to willing . . . . . sometimes one at a time, or two or three, or all at once, forming lust, greed, anger, attachments and vanity or ego, binding us continuously to the Wheel and this world of death, decay and destruction. "Do ye think that the scriptures saith in vain, that the spirit (soul) that dwelleth in us lusteth to envy?" (James 4:5)
Do not continue to follow after the instructions of the foolish; teachers who deceive with the form of knowledge but their truth is based on the law, not God: for the law is the knowledge of sin; but now the righteousness of God (without the law) is manifested. Have the knowledge of God and awake to righteousness: All unrighteousness is sin." (1John 5:17)
What is the level of spiritual discernment if a person has never experienced anything in the spirit, or Spiritual revelation? - ZERO.
Spiritual discernment is to hold yourself accountable, to correct yourself, NOT to hold others accountable or try to correct them, that is their job; your job is to demonstrate the way of righteousness that they might 'pick-up' on it. Also, spiritual discernment is not the ability to read minds, although the mind reading phenomena of the soul does get in the way of the Spiritually inexperienced, who lets the imagery stored in their own soul, affect their thinking.