Celebrated Christian apologist and speaker Nabeel Qureshi revealed he has terminal cancer with doctors giving him an almost zero per cent chance of survival.

The Pakistani-American who converted from Islam before becoming an outspoken evangelist and bestselling writer asked for prayer as his latest round of treatment proved unsuccessful.

'The results aren't good,' he told followers on YouTube. 'The radiation apparently didn't work too well.'

The author of No God But One: Allah or Jesus? is battling stomach cancer and said although the tumour had shrunk there, the cancer had spread through his lymph nodes around his chest, meaning he is ruled out from vital surgery.

'We don't know what's going to happen now,' he said. 'Next week, we will be meeting with our medical oncologist who will be giving us whatever options we have now.'

The heart-breaking video update showed Qureshi saying he 'can't lose hope' and talking about how he didn't want his young daughter to grow up fatherless.

'This is about the worst news we've received since the day we were first diagnosed,' he said. 'And the cancer is now worse than where it was when we were first diagnosed.'