Imam Al-Baqir (a.s.) said:
ثَلثُ قَاصِماتُ الظَّهْرِ: رَجُلٌ إسْتَكْثَرَ عَمَلَهُ وَ نَسِىَ ذُنُوبَهُ وَ أَعْجَبَ بِرَأيِهِ
The three types of individuals who destroy themselves: the one who magnifies his good deed, the one who forgets his sins, and the one who is opinionated.1
Those who magnify their deeds will sit back , well satisfied with their work. This attitude hinders them from progress and development.
Those who forget their sins will continue with new sins everyday instead of compensating for their previous sins. Suddenly one day they will find themselves down in the depths of despair .
Those who rely only on their own opinion will deprive themselves of valuable and essential knowledge and thinking of brilliant minds. They will be repeatedly involved in mistakes and finally their backs will break under the burden of the resulting problems .