Both intellectual evidence and traditional authority alike attest to the fact that on the Day of Resurrection, each person will behold the reward for his good actions. The Qur'an says:
From these verses it is clear that the wicked deeds of man do not obliterate his good deeds. Nevertheless, it must be understood that those who indulge in certain sins (such as disbelief or polytheism), or become apostates, will experience the 'nullification of action', and consequently will find their good deeds wiped out; they are then subject to perpetual punishment:
Taking all of the above into consideration, it is clear that each person of faith will behold the consequences of his good and bad acts in the next world, unless those bad acts take the form of apostasy and the like, in which case, according to the Qur'an and Hadith, all good deeds are negated and lost.
In conclusion, it is necessary to insist on the following point:
Although God has 'promised' to reward the good deeds of the believers and, conversely, has 'threatened' to punish bad acts, there is a significant difference between the two principles-promise and threat ( wa'd and wa'id). For the necessity of keeping a promise is a self-evident intellectual principle, and the breaking of a promise is also, self-evidently, a sin. But as regards a 'threat', the meting out of the punishment threatened is a right possessed by the punisher, but he can also refrain from exercising this right. Thus, there is nothing preventing certain good actions from, as it were, covering over the ugliness and consequences of bad deeds, this being called takfir. 
In the Qur'an, certain good acts are deemed means whereby this 'covering over  by God of bad action is effected, one of these means being the avoidance of major sins:
Certain acts such as making repentance, giving charity in secret, speaking truthfully, and the like, also have this effect; that is, they too attract God's 'covering over' of man's sins.
2. This is the literal meaning of takfir, the verbal noun of the second form of the triliteral root k-f-r, kaffara, to 'cover over', in this context, the 'covering over' of sin, thus, expiation of sin by God; it is not to be confused with the other main meaning of the word- takfir, which is 'to judge someone a kafir'. The Qur'anic use of kaffara is clear from the verse cited above from Sura al-Nisa', 4:31.