One massage therapist “reported details of many encounters over a period of years that she described as rape,” the report says. She said Mr. Zacharias talked with her about topics including her faith and her finances, and she came to think of him as a “father figure.” After he arranged for his ministry to provide her with financial support, however, he demanded sex, according to the report. Mr. Zacharias, it says, “warned her not ever to speak out against him or she would be responsible for the ‘millions of souls’ whose salvation would be lost if his reputation was damaged.”

The law firm also found a pattern of intimate text and email-based relationships with women. In reviewing his electronic devices, they found the phone numbers of more than 200 massage therapists and more than 200 selfies, some of them nudes, from much younger women. Mr. Zacharias also used the nonprofit ministry to financially support some of his long-term therapists. The report also reveals that he owned two apartments in Bangkok, where he spent 256 days between 2010 and 2014. One of his massage therapists stayed in the other apartment.

I have never engaged in any inappropriate behavior of any kind

Mr. Zacharias said in 2017 that in 45 years of marriage, “I have never engaged in any inappropriate behavior of any kind.”

The report is a devastating blow for the reputation of a man who was for decades a widely admired evangelical leader. Born in Chennai, India, and boasting impressive academic credentials, he had a reputation among many evangelicals as a worldly and winsome intellectual. His ministry’s motto is “Helping the thinker believe. Helping the believer think.”

Mr. Zacharias specialized in apologetics, a tradition that focuses on making logical appeals for the truth of the Christian faith, and equipping evangelicals to engage non-believers in conversations about faith.

“People in the pews in evangelical churches, when they think of a Christian intellectual, they would have thought of Ravi Zacharias,” said John Fea, a historian at evangelical Messiah College. “He had an immense influence on the way rank-and-file American evangelicals thought about how to defend their faith.”

The ministry appealed to Christian donors

He also built RZIM, which by the time of his death employed more than 100 full-time speakers around the world. The ministry appealed to Christian donors who saw Mr. Zacharias as the rare evangelist who could reach atheists and intellectuals in the academy, corporate boardrooms and other elite spaces. As his health failed last spring, public tributes poured in from high-profile fans including the football and baseball player Tim Tebow and the Christian rap artist Lecrae.

As it turned out, Mr. Zacharias’s academic reputation was built in part on exaggerations. Though he often called himself a “professor” or “research fellow” at the University of Oxford, for example, he had only a loose honorary affiliation with a Christian college there. He had similarly inflated his relationship with the University of Cambridge. And though he used the title “Dr. Zacharias” in many contexts, including in his 2006 memoir, “Walking From East to West,” his only doctorates were honorary, as RZIM conceded in 2017.

Résumé started to crumble

The first accusations about Mr. Zacharias’s sexual misconduct emerged around the same time as his résumé started to crumble.

In 2014, Mr. Zacharias met a Canadian couple, Brad and Lori Anne Thompson, at a fund-raising luncheon in Ontario. They stayed in touch, and eventually Mr. Zacharias invited Ms. Thompson to correspond privately on BlackBerry Messenger. The evangelist was 30 years older than Ms. Thompson, and she saw him as a “spiritual father,” she has said. After she confided in him about her history of abuse and trauma, she has said, Mr. Zacharias began soliciting sexually explicit messages.

When Ms. Thompson told Mr. Zacharias that she needed to tell her husband about their relationship, Mr. Zacharias threatened suicide, according to leaked emails first published by the blogger Julie Anne Smith.

Mr. Zacharias co-owned two day spas near RZIM headquarters

After a lawyer for the Thompsons approached Mr. Zacharias privately in 2017, he sued the couple, portraying them publicly as serial extortionists and saying that Ms. Thompson had sent him the explicit messages against his will. The suit ended in private mediation, and all parties signed a nondisclosure agreement.

RZIM’s board expressed regret on Thursday for its response to Ms. Thompson’s allegations. “It is with profound grief that we recognize that because we did not believe the Thompsons and both privately and publicly perpetuated a false narrative, they were slandered for years and their suffering was greatly prolonged and intensified,” it said in the statement accompanying the report.

Mr. Zacharias co-owned two day spas near RZIM headquarters between 2004 and 2015, an unusual venture for an evangelist but one he made no attempt to hide. At the grand opening of Jivan Wellness at a strip mall in 2009, speakers included the comedian Jeff Foxworthy; Sonny Perdue, then the governor of Georgia; and the pastor Johnny Hunt, who was the president of the Southern Baptist Convention at the time.