Evan Mawarire had been a strident critic of former President Robert Mugabe and was jailed by the statesman's government after his This Flag movement saw thousands of people protest in the African nation.
He faced 20 years in prison, charged with trying to overthrow Mugabe's government but his charges were later dropped.
Speaking with Premier, the pastor-turned activist said God has called him to fight injustice.
He explained: "It is important for people like myself - like I suppose in the Bible David did - to stand up and say 'is there not a cause'?
"And I think that's what still continues to drive me onwards when I face persecution that there is a cause for our nation; there is a cause for our generation and particularly future generations.
"I have young kids and people have often asked me 'what really drives me or if I'm not afraid...' and I'll tell you the truth, I am more afraid of my daughters 20 or 25 years from now asking me 'dad, why didn't you do anything? Did you not believe God? Did you not believe what your call was' and I think that's what drives me to keep going."
Mr Mugabe who was forced to resign after 37 years in power under pressure from the army and ruling ZANU-PF party.
The pastor said despite Mr Mugabe's removal from office, the country still needs to make changes.
"As Zimbabweans we must realise that we are in this country for a reason and one of those reasons is to stand up and speak truth to power," he said.
"Nobody will do it for us and people are mandated by God to stand up and speak for themselves."
He also said church leaders have no excuse to not fight against injustice.
"There is a call on many pastors, on many people that are in the clergy to stand up for people or for their injustices... when you look in the Bible that is what you see in the characters that stand out including Jesus himself.
Listen to Evan Mawarire speaking with Premier's Eno Adeogun:
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