Sincere Repentance

Immediate repentance from all types of sins is necessary
'Except those who repent, believe and do good deeds: (for) those ALLAH will
exchange their sins for good deeds. Allah is extremely Forgiving and
Merciful.'
*'Allah accepts the repentance of His servant as long as he does not croak
(on his death bed).' 
'*Paradise has eight entrances all of which open and shut except the entrance
of Taubah. This entrance has an angel guarding it so that it does not shut.
So repent and do not despair.'