Why? The First Amendment says: Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
— Were there any laws enacted by Congress at issue here?
Seriously, not a First Amendment issue. At all.
(And no, the 14th does not alter the 1st.)
The state government cannot force someone to be a certain religion here in the USA. That would violate the first amendment.
Students pay to attend Polk College which is a State incorporated College which allows its teachers to force religion on its students. Of course Polk College receives federal funding and as such it cannot force religion on any student, or it would be a violation of the 1st amendment as a matter of Congress making a law giving federal funding to Polk College which has its teacher(s) forcing religion on students, thereby making an effective funding law which establishes religion.
That teachers goose is solidly cooked.