At one point in history, the Roman Catholic Church was the largest land owner in Europe. Given the power of compounding, the length of time for the compounding to take effect plus the huge principal size to start with, the Catholic Church should easily be the world's richest organization today. However, it is not. What happened to the accumulated wealth of the Catholic Church?
Most was circulated back into the community through Church charities and hospitals (scroll down to 'History of charity in the Church').
Some was taken by the state and thus became eventually owned by people (see Dissolution of the Monasteries: Continental Precedents for example).
Some was converted into buildings, icons, frescos, statues and other forms of patronage.
The remainder was converted in real estate, bullion and other investments. This residual might be a modest fraction of the total money that has flowed through the church, but does add up over the centuries.
The simple answer is no one quite knows how much money the Church has retained.