Human beings cannot discover wisdom by our own intellect or effort. Our powers of deduction are limited at best, and our selfish desires make it easy for us to be misguided. The only way for us to find truth is if God gives it to us. If we humble ourselves and repent of our sins and believe in Jesus Christ, then God transforms us by His great power and His Spirit comes inside us. The Spirit of God then gives us great wisdom so that we can properly discern right and wrong more accurately then before:
The person with the Spirit makes judgments about all things, but such a person is not subject to merely human judgments (I Corinthians 2:15 NIV).
A believer who patiently, quietly, listens to the Holy Spirit inside Him can understand many things that others cannot. We can understand people’s motivations in a clearer way than others can. Likewise, those who do not have the Spirit of God cannot judge us, because they do not even have a firm grasp on right and wrong. How then can they understand what we are doing since they are slaves to the flesh rather than to God?
I anticipate, of course, that some people will misuse the passage above to claim that they have a God-given authority to criticize others and tell them what to do. Indeed, anybody can claim to have the Spirit of God inside them. But if you really do have the Spirit inside you, and if the criticisms and judgments that you are spouting really come from God, then they will conform to the fruit of the Spirit. Anything that does not look like this is not from God:
the fruit of the Spirit is love, joy, peace, forbearance, kindness, goodness, faithfulness,23 gentleness and self-control. Against such things there is no law. 24 Those who belong to Christ Jesus have crucified the flesh with its passions and desires. 25 Since we live by the Spirit, let us keep in step with the Spirit. 26 Let us not become conceited, provoking and envying each other. (Galatians 5:22-26 NIV).