“Is the reward of goodness anything but goodness” (Surah al-Rahman, 55:60).
If you are passing along a mountain and say something aloud, you will hear your own voice again after a moment. It will echo or resound.
You will hear once again exactly the same thing which you have said. For example, if you have said aloud 'good', the echo will be 'good', but if you have uttered 'bad', you will once again hear the word, 'bad'.
Similar is the case with our actions. If a person helps his fellow beings, others will also help and honour him. Allah is also pleased with such a person, and showers many more blessings upon him. However, if a man does evil deeds and harms others, he loses all sympathizers and no one turns up to help him when he is in difficulty.
The Almighty Allah says: “Whoever does good, will see the result of his goodness, and whoever does bad, will also see the result of his wrong-doing”.