To make sure I have made my point understandable, Teaching Religion in a Private School is fine, Mandating it in PUBLIC SCHOOLS at Taxpayers expense is not only wrong, but crosses line of sperating church and state,


Prayer in Public School - Drawing the Line of Permissible Expression
The Supreme Court's decisions over the past forty years set forth principles that distinguish impermissible governmental religious speech from the constitutionally protected private religious speech of students. For example, teachers and other public school officials may not lead their classes in prayer, devotional readings from the Bible, or other religious activities. Engel v. Vitale, 370 U.S. 421 (1962); School Dist. of Abington Twp. v. Schempp, 374 U.S. 203 (1963). Nor may school officials attempt to persuade or compel students to participate in prayer or other religious activities. Lee v. Weisman, 505 U.S. 577, 599 (1992). Such conduct is "attributable to the State" and thus violates the Establishment Clause. Weisman, 505 U.S. at 587.

Although the Constitution forbids public school officials from directing or favoring prayer, students do not "shed their constitutional rights to freedom of speech or expression at the schoolhouse gate." Tinker v. Des Moines Indep. Community Sch. Dist., 393 U.S. 503, 506 (1969). In addition, the Supreme Court has made clear that "private religious speech, far from being a First Amendment orphan, is as fully protected under the Free Speech Clause as secular private expression." Capitol Square Review & Advisory Bd. v. Pinette, 515 U.S. 753, 760 (1995). Moreover, not all religious speech that takes place in the public schools or at school-sponsored events is governmental speech. Santa Fe, 530 U.S. at 302. For example, "nothing in the Constitution ... prohibits any public school student from voluntarily praying at any time before, during, or after the school day," and students may pray with fellow students during the school day on the same terms and conditions that they may engage in other conversation or speech. Santa Fe, 530 U.S. at 313.

The difference here is is
if a student wants to pray or study privately in public school, that is acceptable, it is not acceptble to MANDATE it in Public Schools