One of satan's treacherous methods is to get people to cover up the evil they do by hiding behind a facade of innocence. He also shows those under his influence how to hide the evil they do.
Innocence is not a quality that people often stress in their daily lives. A good person behaves correctly; and everything he does is out in the open for all to see, not hidden. For this reason, he doesn't need to prove how well-intentioned and innocent he is. But those who do evil are always uneasy, knowing what they have done in secret. There's always some risk that what they have kept secret will come to light at any moment. To make themselves appear blameless in such an eventuality, they do everything possible to strengthen the impression that they are well-intentioned and innocent. In the same way, if the evil they do is discovered, they hide behind their innocence again, deceiving others into coming to their rescue.
But by taking refuge in innocence, they intend to repeat their hidden misdeeds if the need arises. They think that they will be much better able to make people around them accept what they've done if they cover it up well. If their pretended innocence yields results even once, they assume the same method will be successful every time.
Along with the proofs they offer for their innocence and to appear blameless, they also want to quiet their own consciences. This is because every evil act disquiets the human conscience. A human being who commits an evil act knows that it is against his conscience and, to escape the pangs of remorse, makes up excuses to make himself comfortable and justify what he did. But the only remedy for this pressure from one's conscience is to live according to the moral teachings of the Qur'an, where Allah tells us that we must repent when we commit any evil act and change the evil into good by performing pious works. As long as a person does not practice the morality of the Qur'an and tries to cover the evil he has done with a false veneer of innocence, he will only be drawn into more evil behavior. Besides, as the Qur'an says, every evil act will certainly be of no avail:
If anyone wants power, all power belongs to Allah. All good words rise to Him and He raises up all virtuous deeds. But people who plot evil deeds will suffer a harsh punishment. The plotting of such people is profitless. (Surah Fatir: 10)