When I first read these verses, they strongly reminded me of a particular high school clique- the wannabe’s. There were the jocks, drama kings and prom queens, the nerds, the losers… but the most despicable ones were the “wannabe’s”- two-faced, back-stabbing, chance-sniffing, attention seeking low files that everyone preferred to keep away from once their façade gets blown. You see, the fiasco they create is not just restricted to high school and neither is their hypocritical trait something of the new. It just fashions itself into a different name with different times.
-15-وَإِذَا لَقُواْ الَّذِينَ ءَامَنُواْ قَالُوا ءَامَنَّا وَإِذَا خَلَوْاْ إِلَى شَيَـطِينِهِمْ قَالُواْ إِنَّا مَعَكُمْ إِنَّمَا نَحْنُ مُسْتَهْزِءُونَ -14- اللَّهُ يَسْتَهْزِىءُ بِهِمْ وَيَمُدُّهُمْ فِي طُغْيَـنِهِمْ يَعْمَهُونَ
And when they meet those who believe, they say: “We believe,” but when they are alone with their Shayâtin (devils – polytheists, hypocrites), they say: “Truly, we are with you; verily, we were but mocking.” Allâh mocks at them and gives them increase in their wrong-doings to wander blindly. [02:14-15]
The hypocrites mingle with the Muslims, proclaim their faith and pretend to be believers, loyalists and friends- to mislead and deceive the believers and to trick them into thinking they are their allies.They want to have a share of the benefits and gains that the believers might possibly acquire- like the spoils of the battles in which the Muslims were victorious.
Under the hood though, when they are alone with their Shayatin, they assure them that they are definitely in league with them and not the believers.
‘Shayatin’ refers to devils, such as their leaders and masters among the rabbis of the Jews, hypocrites and idolators. Ibn Jarir said, “The devil is any creation that is mischievous- that leads a person astray. There are both human devils and Jinn devils as deduced from verse (6:112)”. 
Allah answers the hypocrites and punishes them for their behavior by not directing them to His path and leaving them to wander blindly in the pits of hypocrisy with a free rein on sins. Since they have chosen this road themselves, they can just as well stay this way forever. He (swt) has explained this verse in another part of the Quran- “And let not the disbelievers think that Our postponing of their punishment is good for them. We postpone the punishment only so that they may increase in sinfulness.” (3:178)
What can be a worse punishment than this? To be blinded from the truth, plagued with hypocrisy and away from Allah’s Mercy… Truly, guidance is given only to those who seek it, and not to those who reject it or mock it.
1. Tafsir ibn Kathir