NEW YORK—It's more than two weeks since the events in New York City, Washington and Pennsylvania, which brought the world to a standstill and claimed the lives of more than 5,000 people. Nearly everybody knows somebody who lost a life or who has been affected by this terrible act.

I was less than a mile from the World Trade Center complex at 8:48 a.m. on Sept. 11 when the first tower of the World Trade center was struck. Thoughts that an airplane had flown in too low and missed the airport crossed my mind. That hundreds of people were injured or killed was catastrophe enough for me.

But when the second plane appeared, racing fast and furious into World Trade Center Two, I was devastated. This was no accident but a deliberate act of terrorism.

Even as a child, in my village in County Donegal, Ireland, I heard daily of acts of terrorism in Northern Ireland. At 11 years of age, I saw the pictures of two toddlers on the front page of our local paper—their parents had been shot dead as they watched television in their living room. “Sectarian killings” were the words used to describe the killings. (Sectarian means when people are killed solely because of their religious beliefs.)

I called it murder. I called it terrorism. I also heard terrorist groups give so-called “apologies” when they had shot someone mistakenly. They called it “collateral damage.” Throughout my life, I feared crossing the borders into Northern Ireland for fear that I too could become collateral damage.

Later on I spent several years as a correspondent in war-torn Bosnia. Again, I saw the lives of innocent people taken away in the so-called name of religion. Bodies were strewn across the streets of villages that had been bombed. Entire families were wiped out.

People, many children among them, who survived the raids on the villages, were rounded up like cattle and forced into camps. They had little or no food. They also faced the hardships of the severe Bosnian winters.

Zoritsa, a Serb from Sarajevo, lost her husband in a raid on the city. Ivan, a Muslim from Mostar, lost two of his children when shells struck them as they played in the park outside their house. Donna, an Irish woman and Catholic who had married a Croatian, watched and cried helplessly as her husband was taken from their home in the middle of the night. He had been called to fight on the front lines.

It mattered little anymore what religion they were. They had all suffered at the hands of hatred.

But I didn't expect to see that same hatred in the heart of New York City.

When Father Werenfried van Straaten, the founder of Aid to the Church in Need, saw the images of the horrific attack on this city, he said he too was transported back in time—to World War II. “Thousands of innocent people met their death, then as now,” he wrote in a Sept. 18 letter to our staff. “Who can find the words to explain such madness when individuals can go so far in their boundless hatred that their own lives are of no importance any longer, merely in order to spread chaos and destruction?”

It was true in Bosnia. It is true in Northern Ireland. It is even true in Jerusalem, the birthplace of Christianity. And now the reality of such hatred is true in the United States.

But in this moment of crisis, know that people from many nations of the world are united behind you. They understand your suffering. They, too, have lost their loved ones.

You, also, can use this opportunity to unite with your brothers and sisters in the rest of the world who have suffered needlessly and dearly at the hands of terrorists. It doesn't matter who we are or where we live. Today, we stand united in our determined struggle against terrorism and in our compassion for one another.

Already we have seen the heroic acts of our firefighters, our emergency services, and our police force. Don't forget the words of one firefighter who continued to search through the rubble day after day at what has now become known as Ground Zero. “If I can save just one life,” he said, “then it is worth more than the two buildings that collapsed.”

Let us together remember these words when we respond as individuals, as Christians, and in our work. Let us remember that as Christians we seek justice and not revenge. Finally, let us remember the words of the Gospel when Jesus asked us to pray for our enemies and to love those who persecute us.

Indeed this is the time to act and not to be afraid to act. We are one world and we are a suffering people. But as Cardinal Desmond Connell, Archbishop of Dublin, said in the aftermath of this horrific attack, “As we act, let us not become the evil we abhor.”

Geraldine Hemmings is director of communications of Aid to the Church in Need USA.