I recently read an article asking this questions in a different way, Is it a sin to send our kids to public school?
In the article David lays the biblical foundation for leading one away from the faith and shows how public schools are doing just that, concluding that sending children to public schools is therefore a sin that we as a nation of Christians need to confess and repent.
I cannot help but to agree with the alarming statistics and biblical references, yet I realize that many families are not financially capable of homeschooling their children. I know that there are some good public schools in some areas of the country and therefore I cannot say that sending your child to a public school is a sin in every case.
But with a 90% chance of falling away from Christianity, the public school is certainly not a good option the majority of parents. At best, if you are going to put your children in a public school consider it a short-term temporary option and continue to look for ways to get your children out of that dangerous environment and into a safer place as soon as possible. Their life and salvation depends on it.