It took forty years of wandering for the people calling themselves Jews to reach a stage where they could set up the system that had been revealed to Moses. It took many years of struggle for the last Messenger to establish a state where the Quran was implemented, having left Mecca where it was impossible to convert the right number of people, so it did not work there.
We have no government in the world which is based on the constitution of the Quran. When we do, then the zakat funds will be collected and distributed to those needing it, as well as helping to run education institutes, hospitals, build road etc, similar to what most of the world do with their tax revenues. Ihsan=balance, is an appropriate term since it is the extremes in capitalism and communism [opposite ideologies] that have and are causing problems in the world, which would be corrected if a more balanced approach was used in both; making them “a system where peace and harmony was acquired in all aspects of life”, i.e. Islamic.
Before this, people will still need help, the poor will need to be fed, clothed, housed, etc and that is why there is a need for charity, Sadaqat. Zakat is the Quranic economic system, sadaqat is the stop gap measure when we need to help others until the system is in place where they will be helped to help themselves. If we go back one verse to 2:214 we see:-
2:214 Or, do you expect to enter the Garden (or regain your lost Paradise) without facing challenges as came to those who passed before you? Hardship and adversity befell them, and so shaken were they that the Messenger and the believers with him, cried, “When will the help of God come?” But, (once the revolution gets going) God‟s help is near.
[3:141, 9:16, 29:2, 33:10. Unity of mankind will not be easy to attain. The differences and prejudices of race, ethnicity, color, creed, wealth and nationalism will always be the barriers to surmount]
The world is in a mess. In order to get to the “promised land”, the heavenly existence on earth, then we need to work hard, overcome our prejudices, etc. The slow and gradual steps this takes will be like a rolling a boulder up a hill, painful and strenuous at first, but once at the top the effort will have been worth it; the trick is not to let the boulder roll down the other side and our efforts go to waste!
The central authority will only come when enough people want it, until then we need to do our bit;people are still crying out for the Quran.