There are some people who will act dishonestly for a minor benefit immediately before them or in the very near future. For example, if no one sees them accidentally scratch the car next to them while parking they just silently leave the scene. A person may deceive other people, but you can never avoid God's eyes. The omnipresent God watches everything. He lavishes good things on those who act honestly and surely repays according to their deeds.
"God will bring every act to judgment, everything which is hidden, whether it is good or evil." (Ecclesiastes 12:14)