Then I will come to them from before them and from behind them and on their right and on their left, and You will not find most of them grateful [to You]." —The Qur'an 7:17
Satan is more interested in people being ungrateful, than simply committing some sin. (Because once you are ungrateful, the door to many more sins will be easily opened.) Is there an ayath or a hadith where it is clearly mentioned that Satan makes a similar remark about people being repentless?