Because they believe that all human beings are created in God's image, Christians value the rule of law and absolute civil equality. Male or female, black or white, young or old, able-bodied or infirm, all are worthy in the eyes of God, possessing innate human dignity.
Because the God whom Christians worship is a personal God who desires a voluntary relationship with each and every person, Christians recognize that religious faith is not something that can be externally enforced. They ardently defend the freedom of each individual to worship God – or not – according to the dictates of their conscience.
Finally, Christians don't have a Pollyanna view of human nature. They understand that human beings are flawed, sinful, and inclined to abuse power. This is why the Founders established a clear separation of powers between three coequal branches of government. They didn't want to concentrate too much power in the hands of sinful people, realizing the damage that could be perpetrated on our freedoms.
For all these reasons and more, Christianity has long been called the "seedbed of democracy." Does this mean that Christian peoples have never committed atrocities against their own? Absolutely not. The point is that the Christian faith offers a moral foundation that condemns such actions. There is no justification for the tyrannical subjugation of others in the Gospels, no matter how much sinful demagogues may try to spin things.
Contrast the Christian political tradition with that of the dominant religious influence in the Middle East: Islam. Setting aside whether or not Islam properly understood is a religion of peace, it is worth considering whether the values that flow out of Muslim culture are compatible with western style democracy.
In most, if not all, Muslim countries religious liberty (often described as the "First Right") is not highly prized. Women are often viewed as second class citizens, and treated as the property of their males relatives in the eyes of Sharia Law. Islam doesn't recognize the separation of church and state, but rather views the state as an extension of Islam and an instrument of coercion for carrying out the agenda of the mullahs.
Religious tolerance and civil liberty are taken for granted in the United States. It is therefore difficult for Americans to accept that the blessings of liberty are not universally available. We are reluctant to articulate the obvious relationship between our Judeo-Christian foundations and our political and civil culture for fear of being labeled imperialist xenophobes. Let's not kid ourselves. Ideas have consequences, and to this point the ideas that have predominated in the Middle East have not lent themselves to liberty and justice for all. It remains to be seen whether Islam is capable of bearing such fruit. Meanwhile, the world is watching and waiting, and people are dying.