The lives of these two pastors could be in your hands, and time is running out.

This was the message conveyed to Christians worldwide who are being asked to speak up for two imprisoned Sudanese pastors who face the death penalty for practicing their faith.

Rev. Hassan Abduraheem and Rev. Kuwa Shamal are facing charges brought against them by the Islamic security forces in Sudan, according to the American Center for Law and Justice (ACLJ), a not-for-profit group advocating for evangelism across the world. The group has launched a global petition on its website asking the world to help save the two men. The petition has been signed by more than 91,000 people as of Wednesday, Dec. 21.

"The lives of Rev. Shamal and Abduraheem hang in the balance," reads the petition. "Both men are facing the death penalty if they are convicted. They have been charged as co-offenders under Sudan's Penal Code of 1991, with charges ranging from waging war against the state and espionage to agitating hatred between classes."

ACLJ Chief Counsel Jay Sekulow warned that if believers don't speak up the two Sudanese pastors could be hanged, pointing out that the charges slapped on them are directly linked to their Christian faith.

"Christian Pastors Hassan and Kuwa need your voice now. Time is of the essence, as the trial continues. Our silence could be their death," he said.

"Other Christians facing death in Sudan are now free because you spoke out. Be heard now for these persecuted Christians," he added.

The Rev. Abduraheem and Rev. Shamal have been arrested, transferred, and re-arrested on multiple occasions this past year in the Islamic-majority country of Sudan, with government officials accusing them of national security crimes, The Christian Post reported.

Sudanese authorities had arrested other pastors in recent years. South Sudanese Presbyterian Pastors Yat Michael and Peter Yein Reith were among them. They were facing a possible death penalty until they were freed from prison in August 2015, according to The Christian Post.

The ACLJ petition warns that there is a "deadly crackdown" on Christians in Sudan.

It notes that Abduraheem and Shamal have already spent at least 12 months in very poor conditions, with their situation unlikely to improve unless others speak out.

Other persecution watchdog groups, such as Christian Solidarity Worldwide, have also been reporting on the case against the two pastors. In May, lawyers for the two men noted that the clergymen are being held in small rooms "with intermittent electricity supply and limited ventilation."

Shamal and Abduraheem are reportedly from the Nuba Mountains in South Kordofan, a region in the country where the rebel Sudan People's Liberation Movement is reportedly based. Sudanese warplanes have been bombing the area since 2011, inflicting an untold number of civilian deaths.