Hujjat al-Islam Imam Ghazali (Allah have mercy on him)  has mentioned following to be the worst sins in Shariah:

1. Associating partners with Allah SWT. Either in His being or His attributes.
2. Considering a sinful act to be within the acceptable limits in Shariah. That is, to consider it halal.
3. Because of failure in one’s efforts, give up performance of  good actions (yaas).
4. Because of being unafraid of Allah SWT, commit the prohibited actions without any reservation (nedar).

We all must ponder over the second crime (in bold).
How many sins prevail in our daily life and how lightly do we take them?

Sayyidi wa sanadi Moulana Mohammad Taqi Usmani sahib (Allah preserve him) tells us to leave all the sins immediately. However, due to our weak determination, non-Islamic surroundings or secular social pressures if we are not able to do so, we should make a habit of repenting for these sins every night, each single day. This will at least keep our balance sheet of deeds clear. And if God forbid, we were to die, there won’t be the huge amount of sins in arrears for punishment waiting.

توبہ میری جام شکن، جام میرا توبہ شکن
سامنے ڈھیر ہے – ٹوٹے ہوۓ پیمانوں کا