The "Pledge of Allegiance" was written in 1892 by a Baptist minister and socialist, Francis Bellamy. He accompanied the pledge with a salute, called the Belamy salute, which looked an awful lot like the Nazi salute. Because of this similarity, FDR did away with the salute during WW II replacing it with the placement of one's right hand on one's heart. It remains that way today.
The original pledge did not have the words "under God" in it. Since it was written by a minster I find this to relevant in that obviously he didn't think it was necessary. The words "under God" were introduced in 1954. Please note the upper-case G which means it is in reference to specific God and not a general term.
Generally, I wouldn't have a problem with this since I don't really care if someone believes in God (or god) or not. This is an individual choice. Since I don't believe in god in the slightest and haven't for several decades, I find it a little disturbing that we are still forcing children to recite this thing. This wouldn't bother me so much if the words "under God" weren't present. Many Americans are atheists or agnostics and have the right to bring up their kids however they choose. A pledge of allegiance to a nation where religion is a choice that has a the words "under God" seems to be a contradiction and extremely unfair to those tax paying individuals who disagree. I don't have any children but I find this to be an injustice regardless. By the time I was in high school, I already considered myself an atheist and would skip these two words while reciting the pledge. I suggest non-believers to do the same.