The benefit of goodness
1- it changes enemy to friend
ولا تستوی الحسنة ولا السیئة ادفع بالتی هی احسن فاذا الذی بینک وبینه عداوة کانه ولی حمیم - surah foselat
34. Nor can goodness and evil be equal. repel (evil) with what is better: then will He between whom and Thee was hatred become As it were Thy friend and intimate!
Reward for good2-
surah alrahman . هل جزاءالاحسان الا الاحسان
60. Is there any reward for good - other than good?