Both have no direct relationship but the free efficient expressions binds them, what are they? Answer: State and Church.
The explanation is the following: State and Church hold no direct relationship towards each other; however it is this separation of state and church that states the government: "shall make no law respecting an establishment of religion or prohibiting the free exercise there of." This means that the government cannot favor one religion or any other and cannot interfere in the free expression of religious beliefs.
People are free to choose and express their own religion and political beliefs and this is what binds both concepts.