Hadith Qudsi 16
AIUlh screens the believer in the world as well as in the Hereafter
16) Narrated Safwan bin Muhriz Al-Mazini: While I was on my way along with Ibn 'Umar taking (holding up) his hand in mine. Suddenly a man appeared to him and said: What did you hear Allah's Messenger saying about confidential talk (secret conversation)? He said: I heard Allah's Messenger saying: (On the Day of Resurrection) Allah will draw near to a believer and put His forgiveness over him and screen him (his sins) then Allah will say: Do you know such and such sin? Do you know such and such? He will say: Yes, my Lord! This conversation will continue) until Allah will make him confess his sins, and thinks that he is ruined. Then Allah will say: I concealed them (your sins in the world) and I do forgive you today. Then he will be given the record book containing his good deeds. As regards, the infidels and hypocrites, the witnesses will say: These are the people who have disbelieved their Lord. Behold! Allah's Curse is upon transgressors.
(This Hadith is sound and reported by Bukhari, Muslim and Ibn Majah)
Allah's mercy can be seen in this world. An evidence of this is that he covers the sinners though He is All-Mighty and AlIKnowing. A further evidence is that he also forgives the same sins in the Hereafter. He may also uncover you as a penaltyin this world. So one should always care that Allah is watching him.