In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Allaah said:

وَمِنَ ٱلنَّاسِ مَن يُعۡجِبُكَ قَوۡلُهُ ۥ فِى ٱلۡحَيَوٰةِ ٱلدُّنۡيَا وَيُشۡهِدُ ٱللَّهَ عَلَىٰ مَا فِى قَلۡبِهِۦ وَهُوَ أَلَدُّ ٱلۡخِصَامِ
وَإِذَا تَوَلَّىٰ سَعَىٰ فِى ٱلۡأَرۡضِ لِيُفۡسِدَ فِيهَا وَيُهۡلِكَ ٱلۡحَرۡثَ وَٱلنَّسۡلَ‌ۗ وَٱللَّهُ لَا يُحِبُّ ٱلۡفَسَادَ
وَإِذَا قِيلَ لَهُ ٱتَّقِ ٱللَّهَ أَخَذَتۡهُ ٱلۡعِزَّةُ بِٱلۡإِثۡمِ‌ۚ فَحَسۡبُهُ ۥ جَهَنَّمُ‌ۚ وَلَبِئۡسَ ٱلۡمِهَادُ

And of mankind there is he whose speech may please you (O Muhammad), in this worldly life, and he calls Allah to witness as to that which is in his heart, yet he is the most quarrelsome of the opponents. And when he turns away, his effort in the land is to make mischief therein and to destroy the crops and the cattle, and Allah likes not mischief. And when it is said to him, “Fear Allah”, he is led by arrogance to (more) crime. So enough for him is Hell, and worst indeed is that place to rest! [Surah Al-Baqarah. Aayaat 204-206]

[وَمِنَ ٱلنَّاسِ مَن يُعۡجِبُكَ قَوۡلُهُ ۥ فِى ٱلۡحَيَوٰةِ ٱلدُّنۡيَا – And of mankind there is he whose speech may please you in this worldly life]: Meaning, the one who hears his speech is pleased when he speaks and thinks that he has uttered beneficial speech; emphasises what he says [وَيُشۡهِدُ ٱللَّهَ عَلَىٰ مَا فِى قَلۡبِهِ – and he calls Allah to witness as to that which is in his heart]- Meaning, he states that Allaah knows that what is in his heart agrees with what he says, even though he is lying regarding what he says because his speech contradicts his deeds. His speech would have agreed with his deeds had he being truthful, because this the case regarding the believers- those who are not hypocrites. And due to this Allaah said: [وَهُوَ أَلَدُّ ٱلۡخِصَامِ – yet he is the most quarrelsome of the opponents]- Meaning, when you disagree with him, you’ll find him to be the most quarrelsome, bigoted and difficult person to deal with, as well as the ugly characteristics that results from this behaviour, which are the opposite of the manners of the believers- those who make ease their way, submit to the truth and pardon people.

[وَإِذَا تَوَلَّىٰ سَعَىٰ فِى ٱلۡأَرۡضِ لِيُفۡسِدَ فِيهَا وَيُهۡلِكَ ٱلۡحَرۡثَ وَٱلنَّسۡلَ‌ۗ وَٱللَّهُ لَا يُحِبُّ ٱلۡفَسَادَ – And when he turns away, his effort in the land is to make mischief therein and to destroy the crops and the cattle, and Allah likes not mischief]- Meaning, when this person – the one whose speech amazes you – is not in your presence, he strives to commit sins that is tantamount to corruption in the earth, so cattle and crops are destroyed as a result of that corruption. The blessings in the vegetations, fruits and livestock decrease and become little due to evil deeds.

[وَٱللَّهُ لَا يُحِبُّ ٱلۡفَسَادَ – and Allah likes not mischief]- Meaning, when it is the case that Allaah does not like corruption, then He has an intense hatred for the person who sows corruption in the earth, even if such a person utters a good speech merely on the tongue (i.e. says one thing and does something else).

This Aayah contains proof regarding the fact that the statements uttered by individuals is not a proof regarding their truthfulness or whether they are upon falsehood, neither that they are righteous nor wicked until deeds ascertain them. And it is obligatory to examine the condition of those who bear witness, the one who is in the right and the falsifier amongst the people based on the righteousness of their deeds – examine the clear indications and their behaviour, and not to be deceived by how they portray themselves and the praise they give themselves.

Then Allaah mentioned that when this person – the one who causes corruption in the earth through acts of disobedience to Allaah – is commanded to fear Allaah, he becomes arrogant and haughty, [ أَخَذَتۡهُ ٱلۡعِزَّةُ بِٱلۡإِثۡمِ‌ۚ -he is led by arrogance to (more) crime]. So, he combines between disobedience to Allaah and being arrogant towards the sincere advisers. [An Excerpt from Tafseer as-Sadi. slightly paraphrased]