According to BBC, Francisco Barajah, founder of the Santa Trindade Evangelical Church, died at a hospital in the city of Beira, where he was evacuated in critical condition.
The publication further reports that After 25 days without food or water, the pastor, 39, had lost weight to the point where he could not stand up.
He had been taken to hospital at the insistence of relatives and followers.
Mr Barajah was diagnosed with acute anaemia and failure of his digestive organs.
He was rehydrated with serums and an attempt was made to introduce liquid foods, but it was too late and and he died on Wednesday.
Members of the Santa Trindade Church said it was common for the pastor and his followers to fast, but not for that long.
His brother Marques Manuel Barajah said the pastor had fasted, but he challenged the medical diagnosis about his death.
“The truth is that my brother suffered from low blood pressure,” he said.
According to the Gospel of Mathew, Jesus Christ of Nazareth fasted for 40 days and nights in the wilderness.