The phrase "under god" was added to the pledge of allegiance in 1954 by President Eisenhower. The phrase is too religious and we have already established that public education and religion should not mix.
We should respect all US Citizens by not using a religious phrase that our children have to repeat every day. Not everyone is Christian and the US should never be seen as a Christian nation, but rather a nation in which all religions are welcome and non religious people are equal in that they are not forced to practice a religion.
It's time to take off "under god" and remind ourselves that public education is about learning math, literature, and science and should have nothing, absolutely nothing to do with religion.