Oh really, then you need to write to SCOTUS and tell them they must stop the teaching of atheism in govt. schools! No honest person can look at the curriculum and deny that. Atheism/naturalism taught as the official state religion in every govt school. When a school teaches a kid that evolved from a chimp, that's not endorsing atheism as a state religion? Or when you teach him situational ethics rather than objective right and wrong - that's not endorsing atheism. It seems everything that is taught in govt. schools is wholly consistent with atheism. Are you going to try to claim that atheism is not a religion? Please try so I can pounce.
I read Nietzche and Satre in school - but I also read Kierkegaard. I don't think either was favored, but Kierkegaard left the greater impression. So maybe I was being taught Christianity.
In answer to your main point - call me whatever name you may want, but I don't think the schools in my part of the world promote atheism. If you think they do, you haven't seen either the school boards or the PTA here.
By the way - schools are local phenomena. There is no federal mandate commanding them to teach atheism. If your kid's school is teaching atheism, then the remedy lies with the parents, by dealing with the board and the administration. But it sounds to me like you don't want them to JUST not teach atheism, you want them to teach Christianity. You know, there are schools for that.
The root of the word "atheism" is the Greek word for "God" (theos?) stemming from the Sanskrit "deva". So a-theism really can only exist in the shadow of God.
But you are right. The religion of secular humanism has a "catechism" that must be believed in on faith, certain "sacred" rituals, and one is considered a blasphemer if one disagrees with the tenets.