All Martyrs of the Catholic Religion possessed the Virtue of Fortitude. This made it possible for them to continue being faithful to the Teachings of Jesus, even when death was the consequence.
The world contains things that frightens us. We would do anything to avoid those things. But if duty calls upon us to face them, we will need Courage to act.
Bravery, like Temperance is a Virtue that acts in our will. It's also called Courage and Strength. With this Virtue, we can overcome fear and we will be willing to face trials and persecutions and still remain firm in our Catholic Faith. It will not matter for us to suffer rejection, abuse, or even physical harm, we will endure it all for the cause of Jesus!
Saint Thomas of Aquinas calls this Virtue the one that braves the greatest danger and therefore meets the risk of life in battle. He also explains that Courage has more to do with endurance, meaning the capacity to bear with extremely difficult circumstances and still keep your faith in God.
We will be also capable of keeping firm in our purposes of doing good and we will endure evil with Courage. But above all, we know that God is with us and it is from Him that this Strength comes!
Paul, the Prince of the Apostles, tells us about his own experiences when enduring persecutions, writing:
“ He has said to me: “ My grace is sufficient for you, for my power is made perfect in weakness” Most gladly therefore I will rather glory in my weakness, that the power of Christ may rest on me. Therefore I take pleasure in weaknesses, in injuries, in necessities, in persecutions, in distresses, for Christ's sake. For when I am weak, then I am strong. - II Corinthians 12:9-10
Since the Virtue of Fortitude acts in our will, it's important for us to submit our will to the will of God in order to grow in this virtue.