Johannesburg - The Zimbabwe pastor who launched a social media campaign criticising the government and then left the country for his safety is calling for a massive but peaceful uprising.Evan Mawarire told an emotional crowd at Wits University on Thursday night that Zimbabwe once was promising but had been reduced to "horror and unimaginable disappointment."Frustration has been growing in the southern African nation amid a collapsing economy and allegations of corruption. People across the country earlier this month staged the largest anti-government strike in nearly a decade.President Robert Mugabe, who has been in power since 1980 and is the world's oldest head of state at 92, has responded by saying that people who aren't happy should leave.'Catastrophe has been our story for far too long'Many have. Most of the people cheering, laughing and crying in the audience on Thursday night were from Zimbabwe, part of an exodus of hundreds of thousands of people into neighbouring South Africa over the years.Mawarire said Zimbabwe's government "cannot deal with people that are genuinely peaceful," and he called on fellow citizens to rewrite the country's future. "Catastrophe has been our story for far too long," he said.He also addressed concerns that he had left the country for good, while acknowledging the risks involved in speaking out."My country is Zimbabwe. It is my home. I live there," he said. "If you are going to arrest me, you will arrest me at home. If you are going to kill me, you will kill me at home."Mawarire has refused to engage in violence."Violence begets violence, and that is something that you and I have to make a decision to be different on going forward," he told the crowd.