Teshuva Is Very Close

The Torah says about the mitzvah of teshuva , according to the Ramban,כי קרוב אליך הדבר מאד בפיך ובלבבך לעשותו – teshuva is very close to us, it's in our mouths and it's in our hearts. When it comes to sins between us and Hashem, this is understandable. But what about when it comes to sins between man and man? If someone took money from someone else but can't find him to return it, how will he…