"It begins to be a practice in one's life, it almost adds to that contour and the shape of one's life and vocation," he said.
Snyder said he started thinking about the priesthood "around my freshman, sophomore year of high school, which is when I would've been involved in this group, and I began thinking about the priesthood and religious life specifically. It was a part of the whole ensemble of what God had for me at that time and for which I'm grateful now."
Father Jack Fitzpatrick, who serves as parochial vicar at St. Paul's Parish in Colorado Springs, also credits DTS with influencing his faith formation in high school.
A kid from a small town, he said there wasn't much going on youth-group-wise in his own hometown, but that he had a few friends from a nearby town involved in a chapter of DTS.
"They were telling me that their youth group was kind of serious, actually, there were a lot less icebreakers...and that really fit me pretty well. I wasn't really looking for games and things like that, I kind of wanted to go deeper into my faith," he said.
"And so anyway, some of these friends of mine invited me to that Dead Theologians Society and I went and it was just awesome. It was kind of exactly what I was looking for."
The saint stories told by the leaders were done in a somewhat "dramatic fashion," he said, and the candle-lit room with holy pictures "lent itself to a more solemn feel...something about the aesthetic really did it."
"It was supposed to mimic the environment of the catacombs in the early Church," he said, "And the idea was, a group of Christians coming together to be encouraged by the virtue of other Christians who had gone before. You know, because that's the whole reason why...the early Christians went to the catacombs, because the martyrs were buried there. And they thought, 'Boy, if we can learn from the courage of these holy men and women who have gone before then we can really be in good shape.'"
Fitzpatrick said he liked the more solemn and traditional feel of DTS compared to other youth groups at the time.
"The Dead Theologian Society really relied on a lot of traditional elements of our faith. Sacramentals were really important. We were all invested in the Brown Scapular. We had this hooded jacket that we wear that the priest would bless when we had earned it. And...there's just a lot of traditional elements in the Dead Theologian Society that honestly, I really didn't find in whatever the standard youth group in 2003 was," he said.
Fitzpatrick also continues to recite the St. Gertrude Prayer for Souls today.
"I mean, the promise associated with it is that every time you say this prayer devoutly, a thousand souls will be delivered from purgatory. So, why not? Why not say that prayer as many times a day you can? I think what was really wonderful about learning that prayer and making it part of my spiritual life was the fact that I don't know that it had ever occurred to me that certain prayers had different promises attached to them," he said.
Because Fitzpatrick had never heard of prayers with particular promises, he started researching what other prayers and practices of the Church came with specific promises. It led him down a path of searching for and discovering many treasures of the faith, he told CNA.
"That prayer really did open a door for me to learn about all kinds of other things in the spiritual life that are a significant benefit, and that people my age certainly would not have been exposed to," he said.
He said he would recommend DTS to any parish looking for a way to get their young people involved and learning more about their faith.
"Think about incorporating Dead Theologians Society as maybe just a part of your overall youth activities that your parish, because for sure kids out there are looking for what DTS has to offer, and if you offer it to them, boy, they will start to grow, and they'll come, and it's just an amazing thing."
Cotter said that in his experience, teenagers "embrace" the idea of praying for the dead as a way to help them to heaven.
"Most teenagers have lived long enough where they've lost somebody. It could be their grandparents, a sibling, parents of friends. So they've had some experience with death that was painful," Cotter said.
"And we can tell them, 'There are things we can do that's very real that can be of great benefit for the one you've lost,'" he added. "They love it and it actually gives great hope. There's an enthusiasm for it. It's a great service.
Cotter said that even though he founded DTS and has traveled the United States and even several countries abroad to spread its mission, few people really know who he is or what he looks like, which is too bad, because he has a pretty incredible bright red mullet.
He said he prefers to keep a low profile.
"There's probably just a handful of teens out of all the (chapters) ever that know who Eddie Cotter is and that's fine because this isn't about me," he said.
"This isn't like the cult of Eddie Cotter's youth group. If I were to pass tomorrow, I mean I'm glad I have people that'll pray for my soul, from DTS, but the apostolate isn't based on me. And I like that. The teenagers now that are in DTS, they weren't even alive when this thing started," he added.
Cotter said he thinks what makes DTS so appealing to teens, and why it has lasted for 23 years, is that it relies on the traditions of the Catholic Church.
"I think it's going to keep going because these treasures of our faith are timeless. The shelf life doesn't have an expiration date on it," he said.
"Everything we do in DTS is as relevant now as it was 23 years ago, as it was hundreds of years ago, and will be hundreds of years from now. And I think that's one of the many strengths of the program is it's not following trend trying to out-hip the teen culture. We're bringing them to our home field advantage which they're not going to get in the secular world."
In 2015, DTS became canonically approved as a private association of the faithful by decree of the late Bishop Robert Morlino from the Diocese of Madison, Wisconsin. Since its founding in 1997, there have been over 18,000 young people in roughly 550 parishes throughout the U.S. and in several foreign countries who have participated in a DTS chapter.
Cotter said learning how DTS has impacted young people is one of the joys of his life. A few years ago, he was at a Catholic conference in Ohio when he was stopped by a van full of nuns who were honking at him. One of them recognized Cotter and had been involved in DTS as a teen.
"I'm blessed far beyond what I deserve because I don't have a theology degree or anything. I was a youth minister at a parish and thought, 'Wow, we can do this,'" Cotter said.
"And so that's why when I very sincerely say: If Eddie Cotter can do this, there's a lot of people out there that are far more gifted than I am. If they decide to either have a chapter of Dead Theologians Society or do something to help save souls for Jesus, they can do it."
Kate Olivera contributed to the reporting of this story.