Oyedepo alighting from one of his numerous jets
Mfonobong Nsehe, who blogs for Forbes business magazine, says pastors own businesses from hotels to fast-food chains.
"Preaching is big business. It's almost as profitable as the oil business," he said.
The joint wealth of five pastors was at least $200m (£121m), he said.
Mr Nsehe said the richest of them, Bishop David Oyedepo of the Living Faith World Outreach Ministry, was worth about $150m.
Bishop Oyedepo owned a publishing company, university, an elite private school, four jets and homes in London and the United States, according to Mr Nsehe.
The Nigerian blogger said Bishop Oyedepo was followed on the rich list by Pastor Chris Oyakhilome of the Believers' Loveworld Ministries. He was worth between $30 and $50m.
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These pastors are flamboyant. You see them with private jets and expensive cars”
"Oyakhilome's diversified interests include newspapers, magazines, a local television station, a record label, satellite TV, hotels and extensive real estate," Mr Nsehe said.