With human discernment, it distinguishes between the mature and the immature physically or mentally (at that level).  With spiritual discernment, it distinguishes between maturity within the church—spiritual maturity.  Remember, discernment is part of wisdom, and so spiritual wisdom is the major factor.  Spiritual discernment is the gift given by God through the Holy Spirit that enables us to rightly judge between good and evil.  It is the comparing of things in life to God's standard of righteousness to see if it matches or contradicts His requirements, so that we can rightly apply the knowledge we acquire during our lifetime in a wise and righteous way.