In the Qur'an, those who describe themselves as believers but who, in truth, do not believe, are referred to as "hypocrites." Although they are invited to belief, the fact that they remain bound to the life of this world, and have adopted a way of life contrary to the morality of the Qur'an leads these hypocrites to adopt an insincere way of speaking, because there is a profound difference between their true sentiments and the ones they try to show to the faithful.
Hypocrites interpret the Qur'an in a corrupt manner. This distorted logic is also reflected in their speech. They interpret the verses of the Qur'an according to their own desires and passions. However, such ways of speaking are a sign of their true selves. This situation, which is highlighted in this verse of the Qur'an, "If We wished, We would show them to you and you would know them by their mark and know them by their ambivalent speech. Allah knows your actions." (Surah Muhammad: 30) is a help to believers from Allah. In this way, the faithful may recognize the insincere who are trying to infiltrate themselves amongst them.
Sometimes, hypocrites try to make their insincere speech seem reasonable by ornamenting it. But when examined closely, it can be seen that this is a Satanic form of speech which only encourages further insincerity:
When you see them, their outward form appeals to you, and if they speak you listen to what they say. But they are like propped-up planks of wood. They imagine every cry to be against them. They are the enemy, so beware of them. Allah fight them! How they are perverted!
Muslims immediately detect the way of speaking of insincere people and carefully avoid speaking in a similar way. However, if some of the faithful behave like hypocrites, this does not definitely establish that they are hypocrites. Believers are progressively educated throughout their lives. During that time, they may make many mistakes or behave wrongly, and of these mistakes may be some similar to those of hypocrites. However, what is important is for those believers to be able to see their mistakes, and correct them and to achieve a level of morality by which they will not repeat the same errors. That one feels a sincere regret and changes one's behavior, in keeping with the Qur'an, shows that he or she has purified himself and sought to act sincerely. If hypocrisy in speech is stubbornly adhered to, however, that is a very different matter.
