An American-Iranian pastor imprisoned in Iran because of his faith has released a letter detailing his abuse.

For the first time, Pastor Saeed Abedini admitted to his family that he's facing "horrific pressures, violence, and psychological warfare."

The 32-year-old father of two wrote that the conditions inside Evin Prison where he is being held are torturous.

He said they are "so very difficult that my eyes get blurry, my body does not have the strength to walk, and my steps become very weak and shaky."

**Read Pastor Abedini's prison letter here.

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"They are only waiting for one thing, for me to deny Christ. But they will never get this from me," he said.

Abedini's wife, Naghmeh, expressed her concern for her husband.

"It is heart wrenching to hear of Saeed's continued abuse and torture in the Iranian prison," she said. "He continues to face life-threatening abuse at the hands of the Iranian officials simply because of his faith in Jesus."

Despite the torturous conditions, Abedini offered encouragement to others who face difficult challenges.

"Maybe you are also in such a situation, so pray and seek God that He would use you and direct you in the pressures and difficulties of your lives," he wrote.

Last week, the American Center for Law and Justice filed a petition with the U.N. Human Rights Council for Abedini's release. Several members of Congress have also urged Secretary of State John Kerry to press for the American pastor's release.

"The letter also underscores the need to move quickly. A U.S. citizen is in failing health from beatings and abuse - a menacing scenario that should command the full attention and engagement of the U.S. government," ACLJ Executive Director Jordan Sekulow said.