There are a lot of dangerous verses in the Bible. Dangerous that is in the hands of people who put self ahead of God and others. One of the more dangerous of these is found in 1 Corinthians :
"The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him. and he cannot understand them, because they are spiritually discerned." (1 Corinthians 2:14)
See the danger? I have often heard this verse used when one person wanted to justify his actions. "You don't understand because you don't have the Spirit." A terrible accusation to try to cover selfishly motivated decisions. The facts are not that difficult to understand; the Spirit will not do anything contrary to or outside of the Bible. That is how I judge the decisions and actions of a person.
It is true that those without the Spirit cannot discern spiritual matters but this speaks more to those in the world than in the Church. That is not saying everyone who claims to be a beliver is but most are. Those without the Spirit probably will not judge by the Word but instead by their own selfish interests. For those with the Spirit Paul reminds us:
"But we have the mind of Christ." (1Corinthians 2:16)
So what does that have to do with anything? We have the mind of Christ via the Holy Spirit. And how can we tell if a person has the mind of Christ? They are the ones who show in their actions that they thoroughly understand what Jesus meant when he said that the first will be last and the last first. What is the mind of Christ? Check out Philippians 2:
"Your attitude (mind) should be the same as that of Christ Jesus: Who being in very nature God, did not consider equality with God something to be grasped, but made himself nothing, taking the very nature of a servant, being made in human likeness." (Philippians 2:5-7)
Those who have the mind of Christ also possess a servant's heart. That is our Lord's heart, that of a servant's. Much of the New Testament confirms this mind attitude. A person without the Spirit cannot understand this and are instead motivated by their own needs. This is how we discern spiritual matters, from the perspective of selflessness, as a giver, as one who doesn't think twice about sacrifice, who gladly submits when the Father says 'do'.
This is why it bothers me so much when people try to justify their selfish actions by saying "you don't understand". Perhaps we understand more than they realize, discerning more than they intend to reveal. The Kingdom is about servant attitude not selfish lordship over people. It comes from a place of Christ's love not of control. Perhaps a few more of us need to go back and meditate on the cross again, asking for help to understand 1Corinthians 13. Yes indeed, Spiritual things are discerned by those who have the Spirit.