One of the greatest orders from Allah is zakaah:
Zakaah in Arabic means growth, blessing and purification.
Islam is the religion of justice. Islam assures the welfare of the individual and the group. The wealthy must pay zakaah to the poor annually. From Islam Q&A:
Question:
If someone is extremely wealthy how much of their wealth should they keep for themselves? Are they allowed to buy a big house or should they give more money to the poor?
Answer:
Praise be to Allaah.What is obligatory on the wealth of the rich is zakaah; whatever is left after paying zakaah, even if it is a lot, is halaal (permissible) for them and it is permissible for them to buy a big house, but they should avoid extravagance because it is haraam in Islam even if the extravagant person is rich, because Allaah says (interpretation of the meaning):
“… and waste not by extravagance. Verily, He likes not those who waste by extravagance.” [al-An’aam 6:141]
It is mustahabb for them to give charity to the poor apart from zakaah, and the best charity is that which comes from richness. According to Islam, they are also obliged to honour their guests and help those who are in desperate need, and to give to poor people who ask for help – even if they have already paid their zakaah.
And Allaah knows best.
Charity is highly rewarded. Drawing a smile on others' face, helping people in need, offering water for free on the road, giving extra food to hungry people, ... etc. each of these is related to justice and peace.