A cardinal from Washington urged Catholics to show solidarity with their persecuted brethren around the world.

"(W)e can go out those doors with ashes on our forehead" as a public display of faith," Cardinal Donald Wuerl said on an article in the National Catholic Register.

In his homily on Ash Wednesday he reminded parishioners that while they enjoy that freedom in the United States, there are "parts of the world where (an ash mark) will just as well be a death certificate."

Cardinal Wuerl's sermon comes in the wake of the recent martyrdom of 21 Egyptian Copts in Libya by the Islamic State. The Egyptian Copts were kidnapped by armed groups loyal to ISIS in January and December. The Islamic State published a video depicting their brutal beheading of the Egyptian Copts, triggering joint action between the Egyptian and Libyan air force.

In addition, the United Nations Commission of Human Rights has recently published a report revealing that Libyan armed groups are likely to target Egyptian Copts more than other minorities in the beleaguered country.

Christians are also persecuted in other countries like Nigeria, where Islamist militants Boko Haram have killed thousands in relentless attacks.

In his homily, Cardinal Wuerl urged his parishioners to identify with and share the pain that their fellow Catholics are experiencing in other countries.

"The first thing we owe our brothers and sisters is a sense of solidarity with them. If they suffer, we should feel that suffering. And we owe them our prayerful support, but we also owe them our voice."

He continued: "The silence of the world community, the silence of all of us in the face of this extraordinary violence against the Gospel of Jesus Christ. 

"As Pope Francis tells us, we have an obligation to one another: We have an obligation to anybody of any faith who has to forfeit their lives simply because they believe."