My kids studied religion in school. But that was mostly a study of the history and social/cultural significance of religion. I remember their amusement at the time that their classes got to the topic of The Diet of Worms.
The school did not try to indoctrinate them with the dogma.
My point: It really depends on what is taught. Properly done, religion should be part of education because of the importance of religion both historically and within modern American culture.