Matthew 5:46

For if ye love them that love you, what reward have you? Do not even the publicans the same?

Underlying these verses is the challenge that men shall be "like their Father who is in heaven." That is what it is really all about, that men should be like the pure and holy God whom they are taught to worship through Christ. God loves sinners, even dying for them while they were yet in sin; so Christians should love all men, sinners included, even their own personal enemies! To live the other way is to be no better than a publican (the gatherer of the Roman taxes); and, in the Jewish lexicon, that was about as low as a man could get! Christ here enunciated a new and thrilling principle to take the place of the old proverb that "One rotten apple will spoil a barrel of good apples!" That is, "One good apple can heal a barrel of rotten apples!" Only Christ could have revealed such an exciting new and effective doctrine as this.