How to Achieve Sincerity

The more a person performs deeds without sincerity, the more miserable and afflicted he becomes There is no doubt that when anyone performs good deeds sincerely like fasting, night vigils, etc., he feels some kind of joy and pleasure within him. 'And they were not commanded except to worship Allâh, sincere to Him in religion, inclining to truth, and to establish prayer and to give Zakah. That is the correct Deen.'