The peaceful vote, which came after two decades of debate, was a stark contrast to the violence that followed 2007's general elections, which claimed 1,300 lives.
Pastors and other clergy, who played key roles in opposing the new constitution, reiterated their concerns over what they see as the document's lax laws governing abortion and its recognition of Islamic courts. Still, the groups largely welcomed the results and expressed optimism that their concerns would be addressed by Parliament.
"We are convinced before God that we have played our role as mandated to us with diligence and respect. God will be our judge," the Kenya Episcopal Conference chairman John Cardinal Njue said.
Njue, the top Catholic leader in Kenya, called on church members to shoot down the draft constitution. The National Council of Churches of Kenya (NCCK) and some evangelical churches also led opposition to the document.
But the church leaders also claimed the voting was not entirely free and fair.
"We are saddened by the fact that the pre referendum process was marked by malpractices and irregularities which continued right into balloting and tallying phases. This calls into question the validity of the process and its outcome," NCCK secretary general Peter Karanja said.
Mere days before the August 4 vote, the church coalition against the constitution suffered a setback when the head of the Kenya's Anglicans, Eliud Wabukala, appeared to change his position. The primate told his congregants that they were free to vote their conscience, a move some saw as an about turn from his earlier calls to vote no.
In another dramatic move, a group of retired clergymen broke ranks with their currently serving colleagues to support the proposed constitution. The group was largely made of fiery preachers known for opposing the government excesses of former President Daniel arap Moi's one-party rule.
After Thursday's announcement that the constitution draft had been appoved by more than a 2-to-1 margin, the group of retired clergy lashed out at their colleagues, saying they had misled Kenyans and that the accusations of vote rigging were baseless.
"They continue to remain dishonest and spreading lies openly. They should say sorry to Kenyans and ask for forgiveness from God," Reverend Timothy Njoya told reporters.
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We earlier covered the vote results in our liveblog.
Earlier Christianity Today articles on Kenya's constitution debate include:
Pointing Fingers in Kenya | Accusations of foreign Christian meddling fly as a constitution vote looms. (July 8, 2010)
Grenade Attacks Were Govt. Plot, Say Kenyan Churches | Six dead, 80 injured at prayer rally protesting revised constitution. (June 16, 2010)
Churches Split Over Constitution | Muslim power, social unrest are key issues in the debate. (Nov 7, 2005)
Mixing Religion and Politics | Churches attempt to overcome constitutional stalemate (April 2004)
Courting Trouble | Christians oppose embedding Islamic tribunals in Kenya's new constitution (August 2003)