We live in a culture where telling lies is acceptable under certain circumstances. Jokes are laced with lies. To make lies seem more acceptable we even label some of them as "white lies". How many of us lie to extricate ourselves from difficulty or to get what we want? We may lie to get married by lying about our age. We lie to get a job by overstating our skills or experience. We may lie to our children to get them to make excuses for us when we don't want to answer the phone or if we want them to listen to us and then wonder where did our children learn to lie? We may lie to our spouses that we do lower our gaze or that we don't waste their money when our actions "speak" otherwise? How many of us lie even jokingly? How many of us think that telling lies is acceptable and won't harm anyone?
Abu Dharr (ra) narrated that, The Messenger of Allah (saws) was reclining amongst the Companions and he said to us:
"Shall I tell you the greatest of wrong actions?" We said, "Yes, Messenger of Allah". He answered: "To associate partners with Allah, to disobey your parents in an ill-mannered fashion..." and then he sat up as if to emphasize his words and said: "lying speech and bearing false witness, lying speech and bearing false witness..." and he went on repeating this until his voice faltered and we became concerned for his health". (Bukhari and Muslim)
According to the above hadith lying is not only a sin but a major sin which the Messenger of Allah (saws) emphasized by sitting up and repeating this over and over again, which he didn't do for the sin of shirk (associating partners with Allah swt) and which he didn't do for the major sin of disobeying parents. Lying is such a huge sin that the Messenger of Allah (saws) mentioned it with shirk and whoever commits shirk and dies upon this will enter the hellfire forever.
Ayman ibn Khuraim (ra) related that once the Messenger of Allah (saws) stood to address the people and said, "People! False witness is equal to shirk!" He repeated this three times and then recited: "So shun the abomination of idolatory and shun telling lies" s22v30 (Ahmad)
Imagine that Allah swt has allowed you the opportunity to say your shahadaah and have the blessings of being a muslim...not just are you a muslim but you love Allah swt, you love His Messenger (saws), you love the Quraan, you love to seek knowledge...you love islam...you have never bowed infront of an idol and you would never worship anything other than Allah (swt)...but because you gave false witness and lied on the Day of Resurrection you will be treated like someone who committed shirk and be thrown into the hellfire!
The Messenger of Allah (saws) said: "The feet of the one who bears false witness will not move from his place until Allah commands him to be taken to Hell." (Al-Hakim)
In the first 21 ayats of surah baqarah Allah swt talks minimally about the believers and the disbelievers and instead focuses mainly upon the hypocrites. Of these verses are those mentioned below:
They (think to) deceive Allah and those who believe, while they only deceive themselves, and perceive (it) not. In their hearts is a disease (of doubt and hypocrisy) and Allah has increased their disease. A painful torment is theirs because they used to tell lies. s2v9-10.
Of all the characteristic traits which lead to their receiving continuous painful punishment, Allah swt explains they were of those who used to tell lies. And as telling lies leads to the hellfire and is a trait possessed by the hypocrites, telling the truth is a trait of piety and leads to Paradise:
The Prophet (saws) said: "Truthfulness leads to piety, and piety leads to Paradise. A person should be truthful until he is written down as truthful in the sight of Allah. Lying leads to deviance and deviance leads to the Fire. A person lies to the point that he is written down as a liar in the sight of Allah." (Riyad as Saliheen.)
So as tempting as it is to lie just that once, just to achieve something, even if it is something noble like getting married, or getting a job or getting your children to stop crying or your spouse not to have a melt down at your secret life, telling lies is a sin on the same level as major shirk, a trait of hypocrisy which can lead to the hellfire.
But the saddest consequence of lying is how it affects our relationship with The King of Kings Allah swt. That although our spouse trusts us, our children trust us, our work colleagues trust us...although our achievements seem exemplary and the people are impressed by our trustworthiness, in reality, Allah swt the All Knowledgeable and All Aware judges us to be a liar. That we may have fooled the people but we haven't fooled Allah swt who knows everything. And in my humble opinion there is a loss no greater than to loose our status and value in the sight of the All Mighty whose Admiration only the worthy and blessed compete for and the unworthy lose (may we all be prevented from experiencing such a loss).