Those five words are printed on my copy of a new biography of Mother Teresa, just published by TIME magazine, “Mother Teresa at 100: The Life and Works of a Modern Saint.” The author, Former TIME religion writer David Van Biema, stopped by “Currents” recently to talk about the book, and when I asked him to sign it, he pulled out a stamp and ink pad and emblazoned that phrase inside the front cover. “Mother Teresa used to say that all the time,” he explained. “She’d count it off on her five fingers. It’s from scripture — ‘whatsoever you do to the least of these, you did to me.’ She always wanted people to remember that.”

I can’t remember the last time an author signed a book with a quote from his subject — let alone, a quote from scripture.

But then, Mother Teresa isn’t just any subject. The book more than does her justice.  It’s a worthy, absorbing, eminently fascinating introduction to her life and work.

It’s chock full of rare and revealing photographs: there she is as a young Albanian woman, Agnes, Gonxha Bojaxhiu; there she is in her sari, with that same determined face, in the early 1950s; there she is in that now-iconic photograph, standing outside a house in the Bronx, clutching the hand of a towering, beaming Princess Diana.

But what really strikes you is the wide range of voices that help to tell her story. Besides David Van Biema — a secular Jew, deeply moved by Mother Teresa’s one-on-one contact with the poor — there is a chapter by Fr. James Martin (no slouch when it comes to scribbling about saints, modern and otherwise.) There is also a chapter on her cause for sainthood, written by her postulator, Fr. Brian Kolodiejchuk, MC. And the forward is by none other than Rick Warren, from the Saddleback Church, and the author of “The Purpose Driven Life.”

Well, if any life was driven by purpose, it was certainly Mother Teresa’s.

As Warren notes in his beautiful introduction:

Mother Teresa never told anyone, ‘I’ll care for you if you become a Christian.’ Instead, she offered the same unconditional love our Savior did. By being the hands and feet of Jesus, this petite Albanian Catholic nun became one of the great evangelists of the 20th century…

…The more you care about the powerless, the more power you have. The more you serve those with no influence, the more influence God gives you. The more you humble yourself, the more you’re honored by others. This is the great lesson I hope you’ll learn from this book.

Check it out. It’s slender, it’s affordable, and it’s something you can easily toss in a beach bag and take on vacation. Do it. You’ll be glad you did.

And remember those five words. Count them on your fingers. And then, find a way to make them count for others.