If we try to deceive others we automatically get deceived.
Our ethics, elders often tells us not to try to deceive others on any account. In Tamil, there is a song, 'Emaatraathe, Emaaraathe' (don't cheat) which stresses the same point. I have read one story in relation to this-One man was standing in a queue to offer prayers in a temple. There was a money box on their way to drop contributions. This man had a torn ten-rupee note in his hand and he said to himself that even god would not find out had put in the torn note. As he neared the box, someone behind him gave him, a two thousand rupee note and thinking it was that man's donation, he put it in the donation box. When he came out of the temple, he saw that man again. He told him, "Sir you are really great to have contributed two thousand". Seeing the shock on his face, he continued, "Sir, it was your money that fell down from your pocket that I had given to you".
He heard God laughing and saying, "And you were trying to deceive me?"