Blackening of Heart
The Prophet (sal Allahu alaihi wa sallam) said: “A person regularly tells lies and adopts falsehood (as his policy), till a black point is imprinted on his heart, and slowly and slowly the whole heart becomes black. At that time, his name is entered in the list of liars before Allah.” [Imaam Maalik]
Each lie, each untruth, each dishonesty, marks our heart with a black dot. That person becomes doomed whose heart gets covered with so many black dots that it is entirely blackened. That is the point of no return, at which his name is put on a list of inveterate liars.
The only way to wash away the dots already present on our hearts is to sincerely repent of our misdeeds. Repentance includes an honest vow to oneself and Allah (subhana wa ta’ala) not to repeat the evil deeds one committed.