Having someone silently mouth the words you are speaking is called echolalia. Many of us know someone that does this and there are a few causes to address, notably left hemispheric brain injury. Also, some subconsciously do this conversational lip-sync to enhance memory when short term memory is becoming problematic. Nonverbal echolalisis is normal in some, but combined with religion it has proven damaging to entire continents. Religious echolalia is a common practice to polish lies, mimicking and memorizing lines of bullshit horseshit to later flow from the lips of the once silent puppet.
Silently mouthing and audibly floundering apologists have perfected this technique in seminaries across the country. Conversational lip-sync from both sides of the mouth is a skill-set usually reserved for top ventriloquist, but apologists have now taken the industry by storm. Here below our favorite apologist duo, Mel and John caught during warmups

And this dress rehearsal secretly photographed of apologist Wally and Colorstorm. Not sure who is who in this one. 
While each team has their own style, rigorous rehearsal and bromance has made the four indistinguishable in print. The cure to religious echolalia is unbelief. Dry your eyes you weepy guys. Jesus ain’t coming, and the truth, however painful, is a reality you can learn to live with.

Insanitybytes in a paid “Ask the Bigot” performance with pastor Ryan Faust, grace church, Seattle.

Mel learning from dad, eventually honing the craft to blow smoke up peoples asses.
Echolalia (also known as echologia or echophrasia[1]) is defined as the unsolicited repetitions of vocalizations. made by another person (by the same person is called palilalia In its profound form it is automatic and effortless.
(N)ow yo(U) (K)now h(O)w it (A)ll h(A)ppen(S)