More than 400 days ago, Rebekka's father, American Pastor Saeed Abedini, traveled back to Iran to continue work on an orphanage he was building with government approval. She hasn't seen him since.

According to a news release from The American Center for Law and Justice (ACLJ), if the Iranian regime has its way, Abedini will spend the next seven years behind bars on charges related to his Christian faith.

The ACLJ is a constitutional and human rights law advocacy group representing Abedini's wife and two children. It has called his eight-year prison term "a virtual death sentence."

"Every minute, every day Saeed is apart from us is more excruciating than the next," said Abedini's wife, Naghmeh, who lives in Boise, Idaho, with daughter Rebekka, 7, and son Jacob, 5.

She added, "This was the second year that Saeed missed Rebekka's birthday (on September 12). We had hoped that this past year would be the last she would ever have to celebrate without daddy. Now, I am faced with the painful realisation that our kids are growing up without their father. We are praying for a miracle just to be able to see him again."

Naghmeh won't be alone in those prayers.

The ACLJ said on September 26, the one-year anniversary of Abedini's imprisonment, thousands will attend prayer vigils in more than 70 US cities, including Washington DC and the Abedinis' hometown of Boise, as well as 13 countries worldwide, to call on Iran to release Abedini and to pressure their own governments to take diplomatic action on his behalf.

The vigil participants join more than 620,000 people from around the world demanding the pastor's release.

Now, thousands more are urging newly elected Iranian President Hassan Rouhani to release Pastor Saeed through an online letter-writing campaign.

"With each passing day in prison, the situation facing this American pastor becomes more grave," said Jordan Sekulow, executive director of the ACLJ, speaking in the news release.

He added, "For one year now he has been illegally imprisoned-365 days that has been extrem ely difficult and dangerous for Pastor Saeed and increasingly trying for his wife and children. We realise that international attention-including a statement by President Obama which has yet to come-is a critical part of a global strategy to keep the spotlight on Iran, to keep this urgent human and religious rights case at the forefront. Our legal and diplomatic work continues to free Pastor Saeed. On this critical anniversary, we invite people of faith everywhere to join us at BeHeardProject.com/Saeed."

The ACLJ said that as of now, President Obama has yet to personally mention or speak publicly about this American citizen held captive in an Iranian prison.

However, Secretary of State John Kerry did, however, issue two statements, the most recent coming last month "respectfully" asking the Iranian government to "work cooperatively" to return Abedini to his family in the U.S.

Last month, the ACLJ said, the Revolutionary Court in Iran rejected Abedini's appeal. They reaffirmed his conviction and sentence to eight years in Tehran's Evin Prison because of his Christian beliefs-interpreted by the regime as "crimes against the national security of Iran."

During the past year, Abedini has endured repeated beatings and psychological abuse at the hands of fellow inmates and through interrogations by the Revolutionary Guard. Doctors have confirmed he is suffering from internal injuries that require ongoing medical attention-something his captors have repeatedly denied.

To get involved in the online letter writing campaign visit www.BeHeardProject.com/Saeed