As a missionary working with young people, Feldpausch said he decided to come to the symposium because understanding and communicating the truth of Humanae Vitae is essential in his mission to youth.
"The most fascinating thing about my job in dealing with middle schoolers and high schoolers is that Humanae Vitae, Pope Paul VI's vision, the warnings of Our Lady of Fatima, the writings of John Paul II - they become more relevant," he said.
Feldpausch said his approach to speaking to young people is to flip on its head the cultural narrative that suggests total autonomy and the freedom to do whatever one chooses are the keys to happiness.
"You're finding now in our world, people are accomplishing those things that they think will make them happy, and they're getting to that point and they're realizing that they're not happy," he said.
"So it's beautiful and enlightening to introduce them to [Humanae Vitae] and say hey, I understand where you're coming from...but what if this Church and this faith and this beauty and love and truth...what if that is where your freedom lies? What if that is your fulfillment lies? Just think about that, just think for a minute."
Reghan Methe, a student at Benedictine College, said she came to the symposium to learn how she could practically apply the teachings of Humanae Vitae in the world.
"I am interested in how to implement all these things that we're learning here, because we have all of these great classes but that can keep it in a very abstract or intellectual level," she told CNA. "So a lot of people here, with the primary focus being evangelization, it helps to make what you're learning more concrete."
Michele Chambers, who teaches Natural Family Planning in the diocese of Lincoln, Nebraska, told CNA that she found that the symposium was a time to learn from and reconnect with like-minded people before going back to the mission field.
"To have these myriads of people here all on the same team - which when you're in your individual dioceses and parishes, you don't see that as much - it's nice to come and get filled so you can go back and try and do your job a bit better," Chambers said.
She said the teachings of the encyclical continue to be relevant "because even 50 years later, we're still struggling, and we struggled for years before," she said. "Trying to live Humanae Vitae is a very difficult thing no matter what year you're born in, and we have to give people that sign of hope that it can be done."