ROMANS 1 [20] Ever since the creation of the world his invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made. So they are without excuse; [21] for although they knew God they did not honor him as God or give thanks to him, but they became futile in their thinking and their senseless minds were darkened.
Since over 95% of the country is Judeo-Christian maybe we should stick with teaching intelligent design from that perspective.
That's assuming that all Christians think in lock-step uniformity about the issue of creationism or intelligent design.
As with just about every other religion, you can't even get Christians to agree on what it means to be "Christian". Hence the need for Southern Baptists, Presbyterians, Roman Catholics, Lutherans, Seventh Day Adventists, Pentecostals, United Church of Christ, etc.
I dont see why, if you are going to teach Genesis, that you shouldn't teach all the others, given equal scientific validity. A persons religious background shouldn't matter, unless its a parochial school.