Money and credit are useful forms of exchange as a community grows larger. Bartering is convenient when you are living in huts or caves and have very few material goods (including food). But as living standards increase and lives become more stable and organized, bartering can take up an inordinate amount of time and can lead to scarcity (more time spent bartering, less time spent producing goods to barter with).
In a world populated by perfect people and led by a god who provides everything and keeps things in order, money would not be any problem at all. It would work perfectly and suffer none of the issues that occur in an imperfect world.