The hypocrite is content to be far from the mercy of Allah, because his outward actions appear to be in line with Islamic laws; and yet he is heedless and ineffective, mocking and transgressing its truthfulness in his heart.
The mark of hypocrisy is disregard for lies, treachery, insolence, false claims, insincerity, foolishness, error and lack of modesty, making little of acts of disobedience, desiring believers to lose faith, and making light of misfortunes in the faith; pride, praise, praise of love, love of praise, envy, preferring this world to the next and evil to good, inciting slander, love of amusement, dealing with prevaricators, helping aggressive people avoiding good deeds, disparaging those who do good, considering good the evil done by the hypocrite and recognizing as odious whatever good another person does; and many other things like that.
Allah has described the hypocrites in more than one place. He said,
وَمِنَ النَّاسِ مَن يَعْبُدُ اللَّهَ عَلَى حَرْفٍ فَإِنْ أَصَابَهُ خَيْرٌ اطْمَأَنَّ بِهِ وَإِنْ أَصَابَتْهُ فِتْنَةٌ انقَلَبَ عَلَى وَجْهِهِ خَسِرَ الدُّنْيَا وَالْآخِرَةَ ذَلِكَ هُوَ الْخُسْرَانُ الْمُبِينُ
In describing them, Allah said,
وَمِنَ النَّاسِ مَن يَقُولُ آمَنَّا بِاللّهِ وَبِالْيَوْمِ الآخِرِ وَمَا هُم بِمُؤْمِنِينَ. يُخَادِعُونَ اللّهَ وَالَّذِينَ آمَنُوا وَمَا يَخْدَعُونَ إِلاَّ أَنفُسَهُم وَمَا يَشْعُرُونَ. فِي قُلُوبِهِم مَّرَضٌ فَزَادَهُمُ اللّهُ مَرَضاً وَلَهُم عَذَابٌ أَلِيمٌ بِمَا كَانُوا يَكْذِبُونَ
The Holy Prophet said, 'The hypocrite is he who, having made a promise, breaks it; when he acts, he does evil; when he speaks, he lies; when he is trusted, he betrays; when he is given provision, he is reckless; when it is withheld, he makes much of his life.'
He also said, 'A person whose innermost being contradicts his public face is a hypocrite whoever he is, wherever he is, in whatever time he lives, and whatever rank he has.'