Those who think that life is restricted to this earthly life do not put themselves out for others unless they stand to get something out of it, and they will not take the initiative to help someone in need. This is because they do not realise that we will receive perfect recompense in the afterlife for the good and the evil we have done in this world. In some verses of the Qur'an, Allah draws our attention to their perverse way of thinking:

Truly man was created headstrong in greed. (Surat al-Ma'arij: 19)

Have you seen him who turns away and gives little, and that grudgingly? (Surat an-Najm: 33-34)

As for those who are tight-fisted and direct others to be tight-fisted, and hide the bounty Allah has given them, We have prepared a humiliating punishment for those who disbelieve. (Surat an-Nisa': 37)

A person must rid himself of the selfishness and meanness of his self. In this regard, our Lord reveals the following:

So have taqwa of Allah, as much as you are able to, and listen and obey and spend for your own benefit. It is the people who are safe-guarded from the avarice of their own selves who are successful. (Surat at-Taghabun: 16)

For this reason, a person who lives according to the teachings of the Qur'an will avoid selfishness and make an effort during the day to share what he owns with others around him. For example, he will take pleasure in sharing his food with someone who is hungry. He will happily give prized possessions to someone whose need for them is greater than his own. He will give whatever is surplus to his needs to the needy (Surat al-Baqara: 219). He knows that he will receive a greater reward for it in the afterlife. In the Qur'an, Allah shows us the exemplary behaviour in this regard of the Companions of our Prophet:

Those who were already settled in the abode, and in faith, before they came, love those who have emigrated to them and do not find in their hearts any need for what they have been given and prefer them to themselves even if they themselves are needy. It is the people who are safeguarded from the avarice of their own selves who are successful. (Surat al-Hashr: 9)

Believers take delight in the knowledge that their act of self-sacrifice has made someone else happy. They live with the inner peace of mind that comes from acting out of a good conscience and knowing that Allah is pleased. Even when they themselves are in need, they will give up their own rights without a thought. They will never mention their act of self-sacrifice, they will not behave in order to be praised or singled out and they will try to make the other party not feel obliged because of the favour they have done.