McCain was different imo, in that he seemed a fairly decent guy who made a mistake sometime. My main gripe with him was his age, combined with his pick for VP.
With Gingrich otoh his behavior seems institutional.

Btw, the same pastor had a straightforward answer to what you said.
He basically said that if everything was because of what God or Satan wants, there would not need to be a judgement day.
Instead, we received free will, which is good because it allows us control over our lives, but also means that there will be a reckoning for our actions. Even if you are a born again Christian and look to God for your moral compass, you are still fallible because your free will allows you to make wrong decisions.