For many centuries, Catholic prayer books have included instructions on how to pray the Act of Faith, a specific prayer that affirms a person's faith in God.
In a certain cense, the prayer is a shortened version of the Creed, which similarly summarizes a Christian's beliefs.
One of the reasons why it has been given a permanent place in many prayer books is because of the witness of the saints and martyrs, who proclaimed their faith in God, despite threats of torture, or even death.
Here is how to pray the Act of Faith, according to the Compendium of the Catechism of the Catholic Church.