People ask, what is the religion? Lots of descriptions, traditions and motivating stories. It all defines a system that people should follow to remain away from evil deeds and do good. Goswami Tulsidas ji says...
पर हित सरसि धरम नहिं भाई।
पर पीड़ा सम नहिं अधमाई॥
He says...my fellow brother, no great religion can match your doing good to others and there is no sin bigger than to give suffering to others.
It is true that no one can truly feel other's suffering, but you must put it in your heart to always do good to others. Even if one doesn't return the favor or does you bad, you should leave it up to the god. Bible also says, "Turn the other cheek, vengeance is mine, sayeth the lord". Once you start trusting the god completely, he will be there everywhere with you, even if you see him or not. So, never forget what the true religion is.