The Yes side led by President Mwai Kibaki and Prime Minister Raila Odinga bloodied their No rivals, winning with nearly 70 per cent of the vote.
The No side included Catholic Cardinal John Njue, and a host of mostly evangelical church leaders.
The mainstream Anglican church sat on the fence and told its followers to vote according to their hearts and minds.
It is not unusual for churches and their leaders to be involved in politics.
In fact, under authoritarian regimes, as in Cuba (and in Latin America in the era of cruel military dictatorships), the church is often the only alternative political voice.
However, the defeat of the churches in the referendum has helped show something important about how the religion and God markets have changed in Africa.
If the churches had taken the position they did in the Kenya referendum 40 years ago anywhere in Africa, they would have prevailed.
They were very powerful then, and because there were really only two organised Christian religions — the Catholics and Anglicans — they had a monopoly of the God business.
Their following was massive. But God was never the main source of their social power.
In the 1950s and 60s, most “native” children in Africa went to school on church scholarships.
Many of the first crop of African Independence leaders, went to school courtesy of missionaries.
Your priest approved whom you married, and if you fell sick you were treated at a missionary hospital.
As the wealth of the Anglican and Catholic churches declined, and governments took over missionary schools and hospitals, their grip loosened.
However, it was the liberalisation of the spiritual market from the 1980s onwards that finished mainstream religion.
Everyone, even presidents, became pastors and started their little churches.
Where there used to be one big church, now there are a hundred.
Where previously a bishop commanded the loyalty of five million, today he is fortunate to have half a million.
And unlike the churches of old, the myriad new independent churches are mostly parasitic.
They milk their flock dry, instead of feeding them as used to happen in the good old days.
So, in reality, the church used to be powerful, because it gave scholarships, put ugali on your dinner table, and gave free treatment at the missionary hospital.
People obeyed church leaders not because they feared the wrath of God, but because they feared going hungry if they didn’t.
Today, if you get too close to the pastor, you could end up poor after giving him your car and your land so he can serve God better.
The balance of power is demonstrated by what happens in Uganda.
To every church person who is ordained a bishop, President Museveni gives a gift of a brand new Pajero.
Many bishops might risk annoying God, but few will want to incur Museveni’s disfavour — until they have got their Pajero.
This is the age of Caesar, not God.
* Charles Onyango-Obbo is Nation Media Group’s executive director for Africa & Digital Media.