Taking account of ones self is consistently required in all things, whether apparent or hidden. While ordinary people might regard certain sins as unimportant, the believer, when acknowledging the right of Allah over him and his indebtedness to Him, sees them as ugly and dangerous. As a result, he cannot but see his good deeds as insignificant in this light, and therefore, he strives continuously to increase them. The Prophet صلى الله عليه و سلم taught the best supplication for forgiveness:
O Allah, You are my Lord - there is no god but You. You created me, and I am your servant, and I uphold Your covenant and promise to You as much as I am able. I seek refuge in You from the evil I have done. I acknowledge before You Your favor upon me, and I acknowledge my sin, so forgive me. Indeed, there is none who can forgive sins except You.
Repentance is a new beginning, as illustrated in the saying of the Prophet صلى الله عليه و سلم: "Islam destroys what came before it, and repentance destroys what came before it." (Al Bukhari). Therefore, no soul should ever despair - no matter how great its sin - for Allah is near, ever-ready to receive repentance, willing to forgive, inviting all to forgiveness with the words:
"Say, 'O My servants who have committed excess against themselves, do not despair of Allah's mercy. Certainly does Allah forgive all sins, for it is He who is the Ever-Forgiving, Merciful." (39:53)
[Source: Realities of Faith, pp.32-33, Umm Muhammad]
