“Aisha relates: I said: Messenger of Allah (peace and blessings of Allah be to him), the son of Judan established ties of relationship, fed the poor. Would that be of any avail to him? He said: It would be of no avail to him as he did not ever say: O my Lord, pardon my sins on the Day of Resurrection.” (Muslim)
Here the Messenger (peace and blessings of Allah be to him) brings into light the fact that the good deeds of a person who dies in unbelief, will not be of any avail to him in the Day of Accountability.
People generally maintain good relationship with their fellow beings, and do good deeds like helping the needy, feeding the poor, spending in charity, running charitable institutions and voluntary organisations, etc. But the difference between the good deeds of a believer and those of an unbeliever lies in Iman. The Qur’ān repeatedly mentions Faith as the prerequisite for righteous deeds acceptable to the Lord Creator; for man’s deeds, however good and great, have no meaning in Islam if they are done by one who has no Faith. In the Day of Judgement the believers will be rewarded for their righteous deeds done just to seek the Pleasure of God; they will enter the Paradise beneath which rivers flow – for they are khair-ul-bareeyah (the best of creatures). While the good deeds of unbelievers will be of no avail to them only because they are sharrul bareeyah (the worst of creatures) who have no faith in God and the Day of Resurrection.