The real nature of saving and lending gets lost in the modern misconceptions about money. Let's cover some basics.

Saving

Personal saving occurs when you consume less than you produce. When production exceeds consumption, the remainder equals saving.

Production rate less consumption rate = saving rate

Because saving requires consuming less than you produce, saving requires sacrifice. You sacrifice current satisfaction in the expectation of sufficiently greater future satisfaction to justify the exchange. (This amounts to a time preference: valuing a greater quantity of a future good more than a lesser quantity of present good.)

Lending

To lend requires saving (sacrifice)

For lending to occur, the lender must first save a good before he can lend that good. The lender must sacrifice - i.e. consume less of that good than they produce.

To repay requires saving (sacrifice)

The borrower must save before he can repay the loan. In order for the borrower to repay the lender the borrower must sacrifice - i.e. consume less of that good than he produces to have the repayment good in the future.

 

To help you understand some of the material which follows, I will discuss briefly Balance in nature, economics, and financial accounting.