[dragonwriter]

Your interpretation makes the portion in question purely symbolic, since you interpret it's requirements to be exactly the requirements already imposed by the First Amendment.

However, in interpreting a law or portion of a law, courts tend to assume that drafters did not intend to adopt a nullity, and will tend, if interpretations are otherwise equally plausible, to interpret the law so that each provisions has substantive effect.

[AdamSC1]

The First Amendment is far too frequently invoked when it isn't relevant. The First Amendment says that "Congress will make no law respecting the establishment of religion, prohibiting the free exercise thereof; or abridging freedom of speech or the press, or the right of the people of peaceably to assemble, and to petition the government for a redress of grievances."

Marking a child wrong (or right) on a test, is not an act of congress, nor would it be infringing on the rights of the individual to practice their belief.

This clause is protecting that if a student has the right answer, we should avoid weighing any additional belief within it - and while it likely will need a few court cases to clarify all the tests within it, the law seems to be well within the spirit of upholding, expanding and protecting things that first amendment tangential but not currently protected by the first amendment.

We should always interpret things with the best intentions and most reasonable explanations until proven otherwise. In this case, the law is written in a manner that is neutral and prevents penalization or award for content from any religion. If their intention was to accept religious answers, the law would have strictly focused on preventing penalization, or be trying to push the legitimacy of specific beliefs.

Sidenote: The ACLU does a good job of outlining what IS protected within the first amendment according to religion and schools: https://www.aclu.org/other/your-right-religious-freedom