“I was the one, Jesus said, that had knocked at your door. I was the one that was lying in the street. I was the one that died, frozen in that broken home.”

It can be brutal to read Mother Teresa, because if you do, your life has to change.

But isn’t that the case with anything of God?

“Homeless for shelter in your heart, He asks of you… Will you be that ‘one’ to Him?” she once said.

In the new collection released in advance of her Sept. 4 canonization, A Call to Mercy: Hearts to Love, Hands to Serve, Father Brian Kolodiejchuk, MC, the postulator of her cause, collects reflections directly from Mother Teresa as well as testimonies to her witness of mercy.

Perhaps the most important thing to know about Mother Teresa is what Kolodiejchuk points out in the introduction to the book.

“She understood herself to be someone in constant need of God’s mercy, not just in a general way as a sinner in need of redemption, but also specifically as a weak and sinful human being who depended entirely on God’s love, strength, and compassion each day,” he wrote.

In his very first interview, with Jesuit magazines, Pope Francis was asked who he is, and he identified himself as a sinner. This is at the core of Christianity and yet is missed by the world, often because we don’t lead with it, and maybe don’t even believe it.

Mother Teresa isn’t a saint because she was nice to people. Mother Teresa is a saint because she was a sinner who accepted the divine mercy of God into her life, and it changed her. He changed her. In her own poverty, she recognized herself as “one of the poor, identified with them in some way, being in some way in the same condition,” as Kolodiejchuk puts it.

Her successor at the Missionaries of Charity, the order she founded, describes Mother Teresa’s heart as “big like the Heart of God Himself, filled with love, affection, compassion, and mercy.” She reflects: “Rich and poor, young and old, strong and weak, learned and ignorant, saints and sinners of all nations, cultures, and religious found a loving welcome in her heart, because in each of them she saw the face of her Beloved—Jesus.”

She wanted to be “God’s love, His compassion, His presence,” Kolodiejchuk explains, using her words, “wherever she went, so that people looking at her might come to know the God whom she wished to reflect.”

She was not a mystic in the clouds, she was a mystic in the streets, doing what had to be done because Jesus Christ loved her in all her weakness, because she loved Him and looked to him for everything.

She made sure people know that “Before [Jesus] taught the people, He had pity on the multitude, and He fed them.” She explained: “He made a miracle. He blessed the bread, and He fed five thousand people. It’s because He loved the people. He had pity on them. He saw the hunger in their faces and He fed them. And only then He taught them.”

We see the same today, don’t we? That hunger. It’s hard not to see, isn’t it, why she’d be canonized during the jubilee year of mercy? And why imitating her imitating Him is a strategy for evangelization that could get us out of all our current stalemates and destruction.

What a wondrous sight it is to see one who sees Him, as she did, in the people the world would often rather not see – the “disposable” in our “throwaway” culture as Pope Francis might put it. What pain it soothes to live as she did.

That’s why she said: “I must come and give until it hurts.” Because He said He wanted this. And because when you look and take the time to see, you know “Hunger is not only for bread, hunger is for love.” So you must do more.

As much good as so many on the front lines of the field hospital do, as Pope Francis famously described the Church in the world today, the world today isn’t overwhelmed by Christians living in ways of radical love as she did. How often do we not talk or act like a Christian should?

“Love is for today; programs are for the future,” Mother Teresa said.

That’s a lesson for you and I in our daily lives, people in Church bureaucracies, even people in public policy and related enterprises, waiting out the disaster of an election. There are things you can do today to meet immediate needs and work toward renewal.

She continued:

“We are for today; when tomorrow will come, we shall see what we can do. Somebody is thirsty for water for today, hungry for food for today. Tomorrow we will not have them if we don’t feed them today. So be concerned with what you can do today.”

Let’s do something now, “ something beautiful for God,” as our saint would put it.

If there is any main lesson to take from this weekend’s canonization, it’s this: Mother Teresa never did what she did or said what she did because she woke up in the morning knowing she was a saint and had a reputation to live up to. She did what she did and said what she said because she was a baptized Christian and knew the demands of love it required.

You don’t have to be a priest or sister with the Missionaries of Charity to follow her lead. If you’re a Christian, it’s the call. This canonization moment is a gift of an opportunity for reflection and for jumping all in to the life of the Gospel that Mother Teresa made clear is possible even in contemporary times.

Lest we forget, we even have videos and testimony and memory to prove it.