Love those who hate you- and those you hate.

“If you harbor rancor against anybody, pray for him and you will prevent the passion from being aroused; for by means of prayer you will separate your resentment from the thought of the wrong he has done you. When you have become loving and compassionate towards him, you will wipe the passion completely from your soul. If somebody regards you with rancor, be pleasant to him, be humble and agreeable in his company, and you will deliver him from his passion.” -St. Maximus the Confessor; Third Century on love, Philokalia volume II