{St.Matthew 23: verses 25-28} Jesus is talking to the Jewish Leaders. He is making a parable of comparing OUTWARD THINGS unto INWARD conditions of the heart. In reality, Jesus is telling them how hypocritical they are being; by doing things that make them LOOK RIGHTEOUS OUTWARDLY to others, but deep inside their heart, they are full of hypocrisy ( pretense) and iniquity ( sins ).
You know, even unto this day, there are some people who APPEAR to the public as being holy, sanctified, and unstained: but when God begins to UNCOVER, AND UNVEIL them on a constant basis; then we understand that we were only seeing the SURFACE of what was appearing to be right. Now, please understand that only God can see an individual’s spirit (heart ) unless He reveals it to you through DISCERNMENT or through the gift of discerning of spirits.
Jesus was telling many of the Leaders that they appear to men as WHITE SEPULCHERS ( clean & pure) but inwardly were full of dead men’s bones (lifeless & dead). He said they also APPEAR RIGHTEOUS unto men, but within are full of HYPOCRISY & INIQUITY { deception & wickedness}
In other words, people can seem to be without Reproach, but yet they are also without Repentance: they can look obviously Pure, but yet be absolutely Profane: they can be perceived visibly as being Great, but yet inside they are full of filthy lucre & GREED. That’s why we should not just look at the TREE, but inspect the FRUIT that it is revealing: because God will eventually show you the GENUINE ROOT. {Take heed that you be not deceived}