Editor's note: The following column is excerpted from Eric Metaxas’s new book, "7 WOMEN & The Secret of their Greatness" (Thomas Nelson, September 8, 2015).

Last year I was in Skopje, the capital city of what is called by some the Republic of Macedonia and by others FYROM (Former Yugoslav Republic of Macedonia). I was there under the auspices of East-West Ministries of Dallas to speak to that nation’s parliamentary leaders about the life of one of my heroes, William Wilberforce.

One day during my visit, as I was walking through the center of the city, I was surprised to come upon a spot identified as the birthplace of another one of my heroes, Mother Teresa. I had completely forgotten that she was born in Skopje, and suddenly there I was standing on the very site where she had come into the world. The house itself had been destroyed in the great Skojpe earthquake of 1963, but the dimensions of the home were marked out on the pavement. It was incredibly tiny. Standing there I could hardly imagine that the baby born in such a tiny house would go on to become a saint and to inspire millions upon millions around the world.

She certainly inspired me. When I was invited to be the speaker at the National Prayer Breakfast in Washington, D.C., in 2012, I immediately thought of Mother Teresa, whose speech there in 1994 was the only one many people seemed to remember. It wasn’t until I had to write my own speech that I watched hers online.

Mother Teresa was so short that in the video her face is mostly obscured by the microphone, but the moral authority and palpable holiness of this tiny woman is astounding, even when viewed through the less-than-grand window of a YouTube video. When she spoke about abortion, telling President Bill Clinton to “stop killing” these children, to “give them to her,” it inspired me to speak of the taking of unborn life in my own speech. It was the least I could do, feeling so unequal to the high honor of following in the footsteps of this extraordinary woman of God.

She wanted to show the love of Christ in all she did—in helping the malnourished child and the woman dying in the gutter. To her, all these were simply “Jesus in His distressing disguise.”

In modern times, few have had the impact Mother Teresa did. Her very name represented—and still represents—holiness and compassion to many around the world. Catholics, Protestants, Muslims, Hindus, and atheists all respected and loved her. She lived out the commands of Christ: love God, and love your neighbor as yourself. And she deliberately made some of the poorest people on earth her nearest neighbors.

Some years ago, passengers on a Pan Am flight were startled by an announcement from the jet’s copilot. Emerging from the cockpit, he told them that they had a special guest on board: Mother Teresa of Calcutta, founder of the Missionaries of Charity, winner of the Nobel Peace Prize, and friend to everyone from destitute leprosy victims to Pope John Paul II.

The copilot pulled off his cap. If the passengers wanted to assist in Mother Teresa’s work with the poor, he said, they could put money in his cap. He then walked up and down the aisles, and when he returned to the front, he had more than six hundred dollars to present to the tiny, elderly nun.

On principle, Mother Teresa always bought economy class tickets but was routinely bumped up to first class. Flight attendants—who considered it a privilege to serve her—escorted her off the plane to the airport’s VIP lounge and carried her luggage for her. It was an honor simply to be near her. She was a frail treasure that needed to be guarded carefully.

My old boss Chuck Colson, who founded Prison Fellowship and BreakPoint, greatly admired Mother Teresa. In fact, he corresponded with her and kept a plaque on his desk with one of her sayings: “Faithfulness, not success.” When President Ronald Reagan was asked what he told Mother Teresa at the White House in 1986, he said he had listened instead; New York mayor Ed Koch said it was impossible to say no to her when she wanted something. Mother Teresa never thought she was too important to scrub toilets at the motherhouse in India; and she so disliked spending money on plane tickets that she wrote to one airline offering to work as a flight attendant in exchange for being allowed to fly free.

Mother Teresa had a playful side to her personality. Once, when she was invited to hear Mass at the Vatican with her friend Pope John Paul II, she decided to bring a priest along to meet him. But the Vatican had not invited the priest, and showing up uninvited to see the pope in his apartments is like showing up uninvited at the White House for a little chat with the president. It simply is not done; in fact, one could get arrested for doing so, or worse. But Mother Teresa got away with it, dragging the embarrassed priest through several layers of outraged security, right into the sanctum sanctorum of the pope’s living room.

Her impact was so great that it wasn’t unusual for a few minutes’ conversation with Mother Teresa to change someone’s life dramatically. Mother Teresa frequently asked strangers on the street for help—such as moving heavy boxes into one of her facilities for the poor. The strangers usually agreed, and when it dawned on them who it was they had assisted, they were overjoyed.

How did Mother Teresa go about loving her neighbors, and why did she love them so richly? Perhaps her vision can be summed up in the words of Matthew 25:34–40, which she quoted often:

Then the King will say to those on His right hand, “Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world: for I was hungry and you gave Me food; I was thirsty and you gave Me drink; I was a stranger and you took Me in; I was naked and you clothed Me; I was sick and you visited Me; I was in prison and you came to Me.”

Then the righteous will answer Him, saying, “Lord, when did we see You hungry and feed You, or thirsty and give You drink? When did we see You a stranger and take You in, or naked and clothe You? Or when did we see You sick, or in prison, and come to You?” And the King will answer and say to them, “Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me.”

Mother Teresa said that she saw Jesus in every man, woman, or child she met, and she treated them accordingly. She thought the biggest problem on earth was being unloved; and if, in her exhaustion, all she could offer someone was a smile, she gave it.

She wanted to show the love of Christ in all she did—in helping the malnourished child and the woman dying in the gutter. To her, all these were simply “Jesus in His distressing disguise,” as she put it. Because of this she was widely considered a saint during her lifetime, long before the Vatican made it official.

Eric Metaxas is the author of several bestselling books, including "Bonhoeffer" and "Amazing Grace."  His latest book is "7 Women and the Secret of their Greatness" (Thomas Nelson, September 8, 2015). His book "Miracles" is just out in paperback from Plume.