For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe. But solid food belongs to those who are of full age, that is, those who by reason of use have their senses exercised to discern both good and evil.
Heb 5:13–14
The Bible defines spiritual mature people as those who have been putting into practice the Word of God and therefore have developed the ability to discern good from evil.
Spiritual maturity is not a reflection of knowledge depth.
Spiritual maturity is the ability to look at people, circumstances, and cultural constructs and decide whether those things are rooted in the goodness of God or the wickedness of Satan.
The spiritually mature people that I know are able to dissect and discern what is happening in our world today. They have the ability to categorize and compartmentalize the news of the day. They see the way things really are. In other words, their worldview is reality.
The danger comes when we have people leading our churches, schools, institutions, and government who lack this ability of discernment. In their confusion and lack of insight, they drive us further into darkness.
The way of the wicked is like darkness; They do not know what makes them stumble.
Proverbs 4:19
Can you see this factor at play around you? Where do you see those who discern good from evil, and those who cannot?