BOISE -- All roads lead to Rome for the world's Catholics.
More than million pilgrims are expected to jam the streets around the Vatican to see popes John the 23rd and John Paul the 2nd made saints.
Pope John opened the windows of the church to the world in 1962. He convened the Second Vatican Council that modernized this ancient faith. Pope John led the church for just five years.
John Paul the 2nd served for 26 years.
The pope from Poland helped bring down communism, was a major figure on the world stage, a charismatic presence with a more conservative approach to Catholic doctrine.
Millions came for his funeral in 2005, chanting santo subito, or sainthood now.
Michael Brown is the communication director for the Boise Roman Catholic Diocese.
They'll be very popular, they'll be well known, and they're both very well loved. Brown said of both pontiffs.
However, church leaders around the world say Sunday's canonization of both popes isn't without opposition.
Many around the world criticize Pope John Paul the second for being silent on the topics of child sex abuse in the church and gay rights.
Then there's the confusing part about miracles.
Not one, but two miracles are typically required for sainthood in the Catholic Church.
In the case of John the 23rd, the first miracle occurred in 1966, three years after he died, and the second miracle was never submitted, and that was waived by Pope Francis, Brown said.
That means Pope John the 23rd is out of the ordinary.
Canonizations usually take places in clusters, and often involve people who have lived unusual and exemplary lives.
What's essential to the process is to investigate the person's life to see if they lived a holy life.
There's also a requirement that saints must perform not one, but two miracles during their lifetime.
After the first miracle, the holy person, pope or not, is beatified. After the second miracle, the holy person becomes blessed, and can become canonized after death.
Despite what some might see as confusing issues, Sunday's canonization will be viewed by millions.
The historic ceremony will be broadcast in 3D and followed on social media.
It even has its own twitter handle - @2popesaints
But if you aren't a Catholic, or religious at all, there's still a reason to care.
The saints are there for inspiration, for guidance, for help, for intercessions, to help people deal with burdens that they bare, and bring them closer to God, Brown told KTVB.