The Macquarie University Student Union is holding firm on its refusal to allow an African evangelist to preach on campus, but Sydney Anglicans have managed to circumvent the ban.

Stephen Lungu was scheduled to speak at the university's amphitheatre in front of the Student Union until the student representative body became aware of the African Enterprise worker's shady past.

46 years ago Mr Lungu, then a homeless teenager in Southern Rhodesia, was recruited by a terrorist group known as the "Black Shadows' to fight for present-day Zimbabwe's independence.

He was converted to Christianity while involved in a plot to bomb a local church.

"I think there must be a misunderstanding here somewhere because Stephen was going to preach about grace and Jesus and the gospel," says the Rev John Gray, one of the organisers of the "Is the world enough?' mission held by St Paul's Anglican Church, Castle Hill.

"We advertised it under the banner, "Terrorist becomes a minister " come and find out why’,“Mr Gray explains.

"So it was a complete life-transforming story and the emphasis would be on the power of God to change a life. And of course, Stephen has not been involved in a gang at all since 1962."

Mr Lungu says the ban has not discouraged him from his desire to make the gospel known. Rather, it has strengthened his resolve. “God gave me strong shock absorbers, so I’m not put off by a situation of rejection.”

“Because I come from rejection, I see all the rejection as part of my training,” he says, referring to his troubled youth, before his conversion.

Student Union out of step

Despite the clarification, the Student Union is refusing to lift its ban.

However the Union's concerns are clearly not shared by the security agencies charged with the safety of Australia's leading politicians.

"It's a total surprise because Stephen spoke at the NSW State Parliament this last week and today (Tuesday), as we speak, he is driving to Canberra to speak to the Australian Parliament," Mr Gray says.

"He has never been banned from speaking anywhere in the world; he's spoken at Oxford University " so that's why I keep thinking there must be a complete misunderstanding on the part of the student union."

An appeal to Macquarie's university administration, however, has opened up an alternative venue on campus.

Mr Gray says there is no intention to moderate the mission's approach.

"He'll say the same thing, he'll just be indoors, but we're hoping and praying that that does not limit the number of people that will hear him," he says.

Mr Lungu will be speaking at 1pm today, in the Price lecture theatre, Macquarie University. Oscar Muriu, pastor of Nairobi Chapel, will be speaking in the university’s amphitheatre.

For more information about the "Is the world enough?' Mission, visit the St Paul's, Castle Hill website.