Let's make this very simple from the Christian standpoint:
If God created human beings to be in His image and likeness, then ALL human beings were, in fact, made in that image. All humans have a soul and, no matter what race, should be loved as a child of God. Any racism, then, can be seen to be against God's holy will.
As a Roman Catholic, there are times when I am utterly disappointed in the people of my Church. Listen to the following story, ... and weep:
I am reminded of the story about Mahatma Gandhi when he was a student in South Africa. He had become deeply interested in the Bible and was particularly impressed with the Sermon on the Mount. He gradually became convinced that Christianity was the answer to the caste system he had experienced in India. So he decided he would seriously explore Christianity and perhaps even become a Christian. One day he went to Church to attend Mass and inquire about instructions in the Catholic faith. But he was stopped at the entrance of the church and gently told that if he desired to attend Mass he was certainly welcome to—in a church reserved for blacks. Gandhi left and never returned.
This is a great challenge to our conspiracy. It is not only to find room in our hearts for a Gandhi, but also to find room for the one who turned him away at that church door. Gandhi, of course, like the Canaanite woman in the Gospels, took the rejection and allowed it to fuel his passion for peace among all races and religions. Like Gandhi, like that Canannite woman, co-conspirators of compassion believe in creating community where all are welcome, where each one finds a home.
The Conspiracy of Compassion: Breathing Together for a Wounded World, Joseph Nassal, p. 97
Of course, we cannot write an editorial for you. However, we can suggest what sorts of things you might say.
I would suggest that the best angle to take on this is to look at the Christian idea of the brotherhood of all people. Christian beliefs hold that all people are brothers and sisters in Christ. Racism is clearly a repudiation of that idea. This is because racist beliefs hold that people really are not equal. A racist person does not believe that people of other races are truly his or her brothers and sisters. This is something that cannot really be squared with Christian ideas of brotherhood.