Many people quarreled about that. Here is my contribution: money is a right, or better, a system of rights. As with all rights, tolerated abuse of rights endangers the system: money for example stops to work where a state prints money in large amounts to pay for state expenses. The special thing about “money right” is that this right can be aggregated. Money is no universal right: there are multiple currencies (but “conversion of rights” is possible here) and there are things that you cannot get though you have “money right”. But money is quite universal and therefore quite useful. As with every system of rights, it only works when people trust it. Because the right to something is not the actual thing, so you need to trust that you can get the thing (things to buy, here) later if you accept just the right now.
So here is the reason why people want to be rich: being rich means to have “many rights”, that is, to be mighty (influential, important, …). The quest for money and for might are essentially the same.
And here is the definition of corruption: if somebody allows to convert “money right” into a right that ought not be convertible to money, this is called corruption. There are multiple right systems, and they must be kept strictly separated for a society to work. Because, parallel right systems make it possible that the concentration of aggregable “money right” does not mean to gain “absolute rights” over other people. In parallel rights systems it is possible for poor people to “get their right” in court (but corruption endangers this). And, in parallel rights systems it is possible for poor and criminal people still to have their basic “human rights”.
By the way, lobbyism has the same dangers as corruption for a society.
Money as a rights system is a self-defined, artificial “universal interface” between people.
To extend the above idea of “multiple rights systems”: why not introduce different kinds of non-interchangeable money? One for basic goods like food and clothing and shelter, one for luxury items and for “investment games”. This should make it possible to guarantee the basic supply of a society even in the harshest economic crisis. It would demand from everybody (or better: from every micro-society like a family) to invest a part of the time for working in the area of basic supply, to get “basic supply money”. Thus it ensures the economic health of a society, because it will always include a strong sector that deals with the basic supply for life.