Having brought the apostles, they made them appear before the Sanhedrin to be questioned by the high priest. "We gave you strict orders not to teach in this name," he said. "Yet you have filled Jerusalem with your teaching and are determined to make us guilty of this man's blood." (Acts 5:27-28)
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.
If the Sanhedrin had been under the Constitution they would have been guilty of "prohibiting the free exercise thereof."
The first thing to notice is that Congress is the only body that can violate the First Amendment. "Congress shall make no law." The Supreme Court held that the first eight amendments did not apply to any state legislatures but only to the national government. After the passing of the Fourteenth Amendment in 1866, the Supreme Court has held that the first eight amendments apply to all state and subordinate governments. Even with this interpretation it is still true that no single citizen can violate the First Amendment. It only applies to legislative, executive, and judicial bodies. Selectively, courts have applied this to school teachers, but not to university professors.