The way investment works is that one person puts money into a business or person and waits until it can pay them back with interest. With that in mind there is always more money later than now. The thing is when people retire they hope to have more money to retire withthan they have now.
The investment is slow though, let's work on a new model?
Let's say the one peron gives the money to one party and then gets the money back immediately? This could be possible by someone buying up the credit and collecting vast sums each month. What should happen is that all investments are handled by the bank and then the bank buys up all the debt. Or, to cut a long story even shorter, the loaner pays them back immediately by loaning money from the bank to pay the party back. This means the person with the money no longer acts as a bank, but the bank acts as the bank. This means the bank incurs an asset in the form of the loan, and the person that lends the money makes it back immediately, at a reduced profit to what they make today, but it frees money up to circulate immediately. The bank only gets involved when there is the credit to buy up, and the lender signs a agreement of insurance with the bank, that they have faith and are liable for the 'debt'.
Or, the debt could vanish! This would mean the debt is bought by the reserve bank, which means there is money going out, then the GDP improves benefitting the state and the debt is written off.
Or, they could all sell the debt to the people, who may invest in the business with little money. Imagine buying a thing that renumerates? A lot of people I am sure would put money into a loan that exceeds twelve percent returns offered by banking.