Lab technician Arif Ferguson, 36, has been forced into hiding after receiving death threats for speaking out against the murder of a government minister.
He received death threats from the Pakistan Taliban and others after sharing his faith with Muslims and expressing his views against the blasphemy laws with a local newspaper.
He condemned the murder earlier this year of Minorities Minister Shahbaz Bhatti, an outspoken critic of the blasphemy law, and told the paper that the situation for Christians in Pakistan was insecure.
Release chief executive Andy Dipper said: "This latest death threat confirms that militants now regard even opposing the blasphemy laws as blasphemous – a ‘crime’ deserving of death.
"They will not permit debate in parliament or in the press. This ratchets up the risk to all Christians in Pakistan who take issue with intolerance and extremism."
Ferguson and his family attempted to flee to Karachi but were tracked down by militants. A safe house has now been found for Ferguson, while relatives are still trying to make arrangements for other members of his family.
He is being threatened by the same militant group that claimed responsibility for Bhatti's murder, Tehrik-i-Taliban Pakistan.
The death threats have plunged Ferguson's family into financial crisis as he and his sisters have lost their jobs.
He remains strong in faith however.
"I trust in Jesus. If I die it will be for Christ," he said.
Release is campaigning for the protection of Christians in Pakistan. In January it submitted a petition with more than 50,000 signatures to the Pakistan High Commission urging the country to do more to protect its Christian minority.
The petition was presented after the murder of Punjab governor Salman Taseer. He was killed by his own bodyguard after suggesting that the blasphemy laws be repealed and that the Pakistani President pardon Christian woman Asia Bibi.
Bibi was sentenced to death last year for blasphemy and remains on death row. She is in the middle of a lengthy appeal process to overturn the judgement.
"Only a handful of politicians have had the courage to challenge the blasphemy laws," said Mr Dipper.
"Two have been murdered and now the killers are threatening Arif Ferguson with assassination – just for wanting a change in the law.
"Pakistan’s leaders must take a stand against this climate of fear and safeguard the freedom to debate – in the press and in Parliament. They must act with courage to end intimidation. And the blasphemy law – which is used to justify religious killing – must be repealed.
"Please pray that the voice of reason will be heard and respected in Pakistan. Pray for Arif and his family – for their protection, support and encouragement. Pray also for courage for all working to see the repeal of Pakistan’s notorious blasphemy laws."