The word Tawbah ("repentance") conveys a profound meaning, one which carries great implications. It is not, as many people think, the matter of mere lip-service, after uttering which a person may then continue in his sin. If you ponder the meaning of the ayah:
"...Seek the forgiveness of your Lord, and turn to Him in repentance..." [Noble Quran 11:3]
You will see that repentance is something which is over and above seeking for forgiveness.
CONDITION 1
That the sin should be given up only for the sake of Allah, not for any other reason, such as being unable to do it, or being afraid of what people will say. The one who does not commit a sin because of reasons beyond her control cannot be described as one who repents. So the liar who is robbed of the power of speech, the adulterer who becomes impotent, the thief who loses her limbs in an accident...all of them must feel remorse for what they have done and give up any wish to do it again. The Prophet (peace be upon him) said:
"Remorse is repentance." [Ahmad and Ibn Majah]
CONDITION 2
The one who repents should feel that her sin is repulsive and harmful. This means that if a person repents sincerely, she cannot derive any feelings of pleasure or enjoyment when she remembers her past sins, or wish to repeat them in the future.