In Dr. Erwin Lutzer's book,"Hitler's Cross", he summarizes four marks of martyr as taken from Eberhard Bethge's "Bonhoeffer: Exile and Martyr". Here is a brief overview of those four distinctive characteristics.
1. "First, the risk of martyrdom is freely chosen... ...martyrs choose the path of suffering in the face of other options. They could have denied their convictions or remained silent. But they spoke out or acted, choosing to obey God rather than man. They understood the risks, but did it anyway."
2. "The second characteristic of a true martyr is that he does not seek to die, but is willing to accept death should it come. He might even greatly fear death, but he fears compromise much more. These people were not looking for death, hoping to be martyred for some noble deed. Most martyrs have a strong desire to live, and forfeit life only reluctantly."
3. "Third, martyrs have a fanatical commitment to a cause that they regard to be more important than life itself..."
4. "Finally, most martyrs believe that to remain silent is to comply with the enemy. They would agree with Abraham Lincoln that "silence makes cowards out of the best of men." This cowardice, martyrs affirm, is exactly what they labored to overcome. Even when given the option of silence, they are so overwhelmed by the greatness of the cause that they speak out or act as emissaries of justice."
("Hitler's Cross: How the Cross was used to promote the Nazi Agenda"; Erwin W. Lutzer; (Moody Publishers; 1995, 2012); pages 167-169)
Given what we see happening around us in our culture, the day may soon come when Christians will have to decide how important to them the Faith really is. May God grant us grace and mercy and fortitude to remain faithful to the end.