Mother Teresa will be canonized on Sept. 4 — the Sunday of Labor Day weekend. Already a saint in the eyes of most people, regardless of religion, she is clearly deserving of this honor.

I’m even more certain of her sanctity now that I’ve written a book about her critics. I was planning a lengthy piece — booklet size — but after I completed the research and started writing, it became apparent that it might be attractive as a small book.

There are many fine books on Mother Teresa. They run the gamut from authorized biographies to devotional and inspirational works, many based on her own reflections. Lacking was a book that directly confronted her critics. That was the void I hope to fill.

I’ve locked horns many times with Mother Teresa’s most famous critic, Christopher Hitchens. We had it out in a formal debate in 2000 (a video is posted online). Subsequently, we clashed many times on TV. I loved debating him — he was quick and tough. But he was no scholar.

A scholar takes the time to provide evidence for his position, and this is where Hitchens failed. His critical book, The Missionary Position: Mother Teresa in Theory and Practice, contains not one footnote, endnote or attribution of any kind. It’s merely an essay of his unsupported opinions.

I told him to his face that his book was a disgrace and that if he were my student, I would assign him an F. Anyone who seeks to take on someone of Mother Teresa’s stature and attempts to show that all previous accounts of her life are wrong, carries a heavy burden. Thus, any book that condemns her without supporting documentation cannot be taken seriously.

Hitchens was not a happy man, but not without reason. When he was a young man, his mother and her lover, an Episcopalian priest, committed a joint suicide. That would rock anyone. He became a chain-smoking alcoholic, filled with rage; he died in 2011.

This may come as a surprise, but Hitchens and I had a few things in common. Though one would never know it by reading his harsh comments on Mother Teresa’s opposition to abortion, he was actually pro-life. He was pleasantly surprised when I commended him for his enlightened position. He was also no fool when it came to Islam. He knew that the radical interpretation of the “religion of peace” led to terrorism and posed a grave threat to the West. We also liked to drink, though I am happy to say that my tastes extend only to beer and red wine.

Hitchens may be the most well-known Mother Teresa critic, but he is hardly alone. They have much in common: Their accusations can be easily disproven, and all are either atheists or socialists — or both. There isn’t a single, dispassionate writer among them, including a trio of Canadian professors who emerged a few years ago. There is a small cottage industry of critics who continue to surface, so I felt compelled to take them on.

My book, Unmasking Mother Teresa’s Critics, will be available on Aug. 18, a few weeks before her canonization. The timing should be ripe for discussion. The presidential conventions are over at the end of July, and nothing much will be going on in August, which is why those out to sunder Mother Teresa’s reputation will appear. Let them. I relish the opportunity to confront them.

Everyone has shortcomings, Mother Teresa included, but her critics are not content to list them. Instead, they pound away by distorting her record and misrepresenting events. Worse, many of her critics are out-and-out liars. I refuse to give these charlatans a break. I have more footnotes (134) than there are pages in the book (115). No one can accuse me of making any of this up.

After reading her critics’ accounts, I’m convinced more than ever that Mother Teresa deserves sainthood. She was a true altruist, one who took self-giving to a new level. Sadly, that’s one reason why socialists hate her: They contend that only government should tend to the needs of the poor. Thus, she was a deterrent to statist prescriptions. Worse, her altruism was grounded in Jesus, and that drives atheists mad.

In 2010, when the Empire State Building’s owner — a militant secularist and left-wing operative — refused to shine the tower in blue and white on the date of her centenary, I led a demonstration in the street. Speakers at the rally came from many religions, ethnic backgrounds and races. It was quite a moment.

Mother Teresa’s big honor now awaits her. This is something that none of her detractors can diminish, not even in the slightest.

BILL DONOHUE, PH.D., is the president of the Catholic League for Religious and Civil Rights.