There is an ongoing warfare between good and evil in this world. Sometimes, good wins the battle; and sometimes, evil rocks the field. Impalpable and hidden the fight may be, we do feel it, take part in it; and ultimately build up or devastate our fate in the Hereafter. At the outset, there is no difference in this regard among those who are sent down to the earth to participate in this fight. This is so maintained because they all are well equipped with an understanding of good and bad; and also with an internally correcting mechanism, conscience. However, if they are observed with a keen eye, one is astonished to see that there is as much a difference among the creation of God as between day and night. There are some who humble themselves and open their hearts to all that is good. And there are those who feel ashamed to face the lower position of humility and thus always prefer to stand as higher as they can. This difference is not God ordained; rather men of choice and freedom yield to the desires of their inner self and wish never to be exonerated. Since they, of their own accord, prefer to be enslaved to what is low and immoral, Allah leaves them to wander blindly on in their contumacy. In short, an evidently clear difference between both pockets comes to be observed even in this world, which shall be made amply visible and apparent in the world to come. 
    The first two incidents that took place in the history of man also reveal the stark reality to which an allusion has just been made. It was indeed a training phase for the parents of mankind. They were to embark upon the expedition of transferring the message of Allah to their progeny. Allah in His infinite mercy arranged for them to practically learn what was expected of them. Hidden as evil was within Satan, it lay open in front of all the candidates who participated in the test. The Almighty commanded the angels and the Jinn to prostrate themselves before a creation of lower stature. Everyone complied with the directive except for Satan. He contemptuously refused to act upon what his Lord asked of him and paradoxically never came to admit his egregious mistake. This only added to his conceit and arrogance that he went as much as to ask further respite from Allah to lead astray Adam (sws) and his children. This manifestly exhibited that the sublime quality of humility could never find place within his disposition. So he, for haughtiness he had nursed, continued to add more vices to his list by betraying the offspring of Adam (sws). 
    On the other hand, we peruse the anecdote of our progenitors—Adam (sws) and Eve (sws); they were the privileged because of the high position that Allah had awarded them by asking the angels and the Jinn to prostrate before them; they were the chosen in that Allah had explicitly demonstrated that it is through their posterity that He would raise men of goodness and decency, who would outshine everyone in the realms of righteousness and piety. In addition, both were stationed in a beautiful garden furnished with everything they would desire. Yet when they erred and did something that Allah had prohibited them not to go even near, their privileged position and rank did not offer any resistance; and they repented and felt more humble than ever. They readily accepted what mistake they had made and then uttered awe-inspiring words to invoke the mercy of the Almighty. These are the words that still move the God-fearing men of faith and have been made part of the Holy Book by Allah.

O Lord, we have wronged ourselves. If you forgive us not and have not mercy on us, surely we are of the lost. (7:23) 

    Thus, two attitudes lead ‘those who err’ to two different destinations. Haughtiness and conceit cause the wrong doers to fall in the frightening pit of hellfire; humility and willingness on their part to acknowledge their mistakes enable them to attain the forgiveness of Allah and enter a place that is all peace and serene. Humility is indeed a great virtue. This is what helps a person obliterate the very possibility of committing a full error as making a mistake is half error and stubbornness not to accept it is full. The Almighty Himself has stressed the need to turn back to Him however gross an error we may have made because there is no fleeing but to Him alone. He has exhorted us to get off the evil path as soon as we become conscious; and then seek His forgiveness. The promised reward would be as fabulous and wonderful as to amaze the true believers: 

And those who, when they do an evil thing or wrong themselves, remember Allah and implore forgiveness for their sins—who forgives sins save Allah?—and [who] will not knowingly repeat [the wrong] that they did. The reward of such will be forgiveness from their Lord, and Gardens underneath which rivers flow, wherein they will abide forever, a bountiful reward for the [good] workers. (3:135-6) 

    The picture that springs to mind of the believers who are the subject of the above verses is that they are those for whom their mistakes are not simply some errors committed. When they err, they feel torn apart. They feel hurt deep down within their soul as if it is ripped to pieces. Tears wet the ground while they keep crying in prostration. In short, they remain restless until they feel a heavenly peace dawned upon them to be sure that they are forgiven. It is they who are promised that their bad deeds shall be replaced by good deeds:

Except those that [truly] repent, believe and do good deeds, for they are the ones, for whom God shall convert their bad deeds to good ones. God is Forgiving, Ever Merciful. (25:70)