There is no such thing as "separation of church and state". Those words don't appear anywhere in our constitution. This is what actually is in our constitution's first amendment:

"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."

Carl