As christians, we are to be good to all men. That is the proof that we are the children of God. Our Father in heaven sends his blessings to everyone. He makes his rain to fall both for the wicked and the righteous. He makes his sun to shine for everyone equally. He is a good God.
It is out of the goodness of God that he sent his son Jesus Christ into the world for our salvation. There is no greater love than this. Jesus demonstrated the greatest degree of goodness when he willingly offered himself as the sacrifice to pay for our sins. The goodness of God for humanity is so great.
As the children of God, we are commanded by our father that we should do good to all men. This is the commandment of God to us. We are to show the love of God to all men by doing good works. The light of God must shine out of our lives through the manifestation of good works. Jesus Christ said that it will be through the good works that we do that men will come to know that we are his disciples.