Fear your sins more than you fear the enemy as your sins are more dangerous to you than your enemy.

When you shoot an arrow of truth, dip its point in honey. 

In the heart there is hardness which can only be softened by remembrance of Allaah, may He be exalted. So the slave must treat the hardness of his heart with the remembrance of Allaah, may He be exalted.
Ibn al-Qayyim