What the... But it IS overpowered!
My God, man! It allows you to run any civic you want at any time for no opportunity cost. If someone says "Organized Religion is really cool, don't you think?" You don't have to tell them to F'off anymore--Just switch, then switch right back to Free Religion on your next turn. If you're attacked and need to bolster your army really fast, you switch to Nationalism and draft a bunch of units, then switch right back ON THE SAME TURN. You effectively are allowed to tack Slavery and Nationalism onto whatever Legal and Labor civics you already use--for no actual cost. Emancipation's upkeep is cheaper than Slavery, it causes unhappiness for non-emancipated civs, and doesn't have the slave revolt bad event. But you still get the benefit.
How is that not busted?
All we're saying is that it should effectively duplicate Spiritual, not completely surpass it.