To become a creditor, you would have to give something of value to another person, who would then be known as your debtor, and that person would of course have to repay you with a set price or something of equal value with what was first lent to the debtor.
Two men meet by chance. Their meeting brings a credit from one and a debt to one. The credit is one's life.
The credit is a life, not once but twice, therefore the debt has to be repaid with a life, right?