HOW LIARS DECEIVE THEMSELVES

Everybody knows that lying is immoral. For this reason, when people lie they try to ease their conscience and find excuses. In fact, what they should do is confess their lies and tell the truth.
In addition, people need to know and recognize the camouflage used by liars so that in the event that they lie, they will be unable to deceive themselves.

Those who claim to lie with good intentions

The best known method people use to deceive themselves is the claim that they have good intentions. For example, everyone criticizes and condemns those who gossip. But those who gossip claim that they do so only with the best of intentions, and so such talk is harmless. A large proportion of liars make the same claim: They have no evil purpose in mind, but are merely lying to defend themselves or to comfort another person. For example, a child who skips school claims that he lies to his mother so that she will not get angry.
Some people say that they lie because they are afraid of losing the love and trust of those close to them. For instance, people who are unsuccessful at work lie to hide their failure in a self-proclaimed attempt to avoid losing other people's respect. Such people try to persuade themselves and those around them that such lies are harmless, since they have good intentions. In fact, in the Qur'an Allah points to those who display a low morality while claiming to have good intentions:

How will it be when a disaster strikes them because of what they have done, and then they come to you swearing by Allah: "We desired nothing but good and reconciliation"? Allah knows what is in such people's hearts. So turn away from them, warn them, and speak to them with words that have effect. (Surat an-Nisa', 4:62-63)

Such people make the same claim even as the angels come to take them in death and even though they are bound for Hell. In short, they continue to pose as good people.

As for those the angels take in death while they are wronging themselves, they will offer their submission: "We did not do any evil." Oh yes you did! Allah knows what you were doing. (Surat an-Nahl, 16:28)

Those who claim that their lies are innocent and minor

Another method of self-deception is the attempt to compare themselves favorably with great frauds and liars in order to convince themselves that their own lies are minor and harmless. Or, they try to diminish their lies by considering them to be innocent and harmless. For example, a child buys something with her mother's money and does not give her the change, claiming that she received none. While the child might think that this is a harmless lie, in reality there are no "minor" and "major" lies, for in the Qur'an Allah orders people to "have done with telling lies" (Surat al-Hajj, 22:30).

Believing they will not be responsible for lies so long as no oath is sworn

A major and quite frequent mistake made by people who do not follow the Qur'anic morality is the belief that they are not responsible for their lies if no oath was made. In addition, when some people are lying, their strange and superstitious actions (e.g., lifting one foot or crossing their fingers) are a sign that such people are truly "ignorant," in the sense that they have no understanding of true morality. To believe that these and other such simple games protect them against sinful acts and absolves them from responsibility in the afterlife makes it clear for all to see that such people do not appreciate Allah as they should. Like a number of false beliefs, such deceitful rationales have no basis in reason or religion. Allah explains it in the Qur'an, as follows:

What is the matter with you? On what basis do you judge? Or do you have a Book that you study so that you may have anything in it you choose? Or do you have oaths that bind Us, extending to the Day of Rising, that you will have whatever you decide? (Surat al-Qalam, 68:36-39)

Trying to cover up one lie with another

Liars are usually caught in their lies. However, because they do not behave according to their conscience, they usually tell another lie to protect themselves from a previous one. Thus, they gradually create a chain of lies. For instance, in order to protest against a friend who has warned him to act in a better way, a person remains silent. When his friend asks why he does not answer, instead of saying that it was a protest, for which he apologizes and regrets, he replies: "I was thinking of something else, and so I didn't reply." When asked what he was thinking about, he lies yet again, for he had stayed quiet only to protest against his friend's words and to annoy him.
All liars continually plan and calculate, and so none of their behavior or speech is natural, straightforward, sincere, or honest.

Claiming that lying is necessary to defend one's self against other people

Sometimes, liars blame the people to whom they are talking for their lies, claiming that they were afraid that these people might harm them in some way. They do this in order to arouse people's pity so that they can justify their lies. For example, when she loses money that has been entrusted to her, she claims that she neither saw nor received it. Or, when he cannot perform an assigned task, he just tells a string of lies about it, such as he had a number of problems and therefore could not do the job and then goes on to describe a number of imaginary events. When his lies are revealed, he says that he lied in order to protect himself.
In contrast, believers fear only Allah and so always tell the truth. Those who fear other people more than they fear Allah do not stay within the boundaries established by Him, and so are able to lie with ease. Even when, as often happens, they are not going to be harmed by other people, their own arrogance encourages them to deny what they have failed or forgotten to do by making excuses. Liars think only about their image in the eyes of others, all the while forgetting that what should really matter to them is Allah's will and mercy, as well as Paradise.

Those who trust in their innocent and childlike appearances

One's physical appearance also can be quite deceiving. Even though some people outwardly appear to be innocent and childlike, this is no indication that they really are so. The truly innocent are those who conform to the Qur'an, hold Allah in awe, and take refuge in Him. Some people believe that an innocent and childlike appearance will protect them in the Hereafter, for if they can deceive people here, why not in the Hereafter? This delusion causes them to believe that they can present themselves as well-meaning people in the Hereafter.
In reality, these people might convince a number of others of their innocence in this worldly life. In the absence of any evidence to the contrary, a lot of people will accept them as honest people, even when they actually are lying. But Allah knows every person's heart and innermost thoughts. People can hide whatever they like from others, but can keep no secrets from Allah. All of their secrets will be exposed in the Hereafter.
There, no trace will remain of their innocent and childlike worldly appearance, for their faces will clearly display their immorality. Thus, such people should not be deceived by the simple, innocent faces that they see in the mirror; rather, they should avoid immorality and all behavior that is contrary to the Qur'an. In one verse, Allah tells us this:

But as for those who have earned bad actions-a bad action will be repaid with one the like of it. Debasement will darken them. They will have no one to protect them from Allah. It is as if their faces were covered by dark patches of the night. Those are the Companions of the Fire, remaining in it timelessly, forever. (Surah Yunus, 10:27)

Those who believe they will be excused if they tell a lie and repent later

Yet another method of self-deception is that liars' claim that they can save themselves by repenting at some point in the future. Of course Allah accepts repentance and forgives sins. However, one's repentance must be the result of a feeling of regret and the decision to avoid committing that particular sin in the future. In the Qur'an, Allah tells us that:

Allah only accepts the repentance of those who do evil in ignorance and then quickly repent after doing it. Allah turns toward such people. Allah is All-Knowing, All-Wise. There is no repentance for people who persist in doing evil until death comes to them and who then say: "Now I repent," nor for people who die as unbelievers. We have prepared for them a painful punishment. (Surat an-Nisa', 4:17-18)

As Allah tells us in these verses, lying with the self-deluding claim of repentance at some unspecified point in the future is no more than a clear manifestation of great insincerity.

Conclusion

As Allah tells us in the Qur'an, "in fact, man will be clear proof against himself in spite of any excuses he might offer" (Surat al-Qiyama, 75:14-15). Whatever excuses people put forward, they know very well that lying is dishonest and immoral. They might convince others that they are justified or innocent, but Allah sees everything and, most importantly, knows all that they have said and their true reasons for saying it, as well as what is going on within them and their hidden thoughts.

Though you speak out loud, He knows your secrets and what is even more concealed. Allah, there is no god but Him. The Most Beautiful Names are His. (Surah Ta Ha, 20:7-8)