North Texas doctors say they know where a recent measles outbreak began.

The Eagle Mountain International Church in Newark is being considered at the center of most of the confirmed 10 cases.

Dr. Karen Smith confirmed the first measles case was from a person that visited the congregation a few weeks ago. That person had recently taken a mission trip to Indonesia, Tokyo, Germany, and Paris. The trip was unaffiliated with the church.

Smith described the person who's believed to have contracted the disease on that mission trip as an ongoing person and "full of hugs." Doctors believe that patient had one measles vaccine instead of the two recommended.

As of Monday, the church confirmed nine cases of measles were within their congregation. The church has advised immunizations for all members and for those choing not be vaccinated, the church is urging self-isolation for 14 days.

Tarrant County Public Health confirmed Tuesday that 7 of the 10 measles cases had not been vaccinated against the disease.

Smith said it was "the grace of God" that led to the initial diagnosis of measles. She says the patient she treated had symptoms of the disease that enabled her to literally diagnose the disease from a textbook. Smith said the illness is unfamiliar to many American doctors due to the widespread use of the vaccines.

Pastor Describes Outbreak as "Spiritual Warfare"

In a sermon posted online last week, the pastor of Eagle Mountain International Church in Newark said that several families in the church are sick with measles.

Pastor Terri Pearsons called this outbreak "spiritual warfare" led by the devil.

She also said the measles is something to be taken seriously, but told her worshippers it's not going to wipe everybody out.

"There's a knee-jerk response to things like this, because that's the health department and CDC's job, to make everyone concerned and aware about it. But I want to remind people my age, remind anyone born before 1957, that we all had measles. We all had the measles when we grew up. We all had the measles and the mumps and the chicken pox," Pearsons said. "So we don't take these things flippantly. We take them seriously. But we keep them in perspective."

Due to the number of infected worshippers, Eagle Mountain International Church held two free vaccination clinics for worshippers and their children, on Friday and Sunday.

The church also hired a cleaning crew to disinfect all equipment and surfaces.

"There will be a massive disinfecting of the entire church, this whole building, the campus, everything," Pearsons said. "Disinfecting of equipment and everything that people touch."

Pearsons also temporarily shut down the nursery, on the health department's advice.

Doctors said many of the cases are connected to one man who recently traveled to Asia, where measles is more common. Many of the measles cases are people who were not immunized against the virus.

Pearsons said it's important to stand together as a church family with strong faith.

"The blood cleanses us from all unrighteousness. And I've got news for you, the measles are unrighteous. This has affected a few of our families, I know a few of our families have been affected by it and it's extremely unpleasant. And so we're going to stand for them," she said.

The number of people sick with the measles is expected to rise over the next few days, according to health officials.

There is a low-cost vaccination clinic at La Gran Plaza in Fort Worth Tuesday for children who don't have private insurance.

NBC 5 reporters Jeff Smith and Eric King contributed to this report.