I don't think McCain could be ambilvalent or indifferent if he tried....he has always been a bit of a maverick in terms of following the crowd. Comments about the circumstances surrounding his first wife etc are not really appropriate to the issue. I think the sum total of his life speaks positively to his character.
Showing up at church has little to do with how much faith one has. I've known those who attend church every time the doors open but have no real love or kindness in their heart and those who attend irregularly who do so more out of show or because it is expected but show no kindness or love towards their fellow man. On the other hand I know those who both attend church regularly and spend their life helping others. The Bible teaches "He who has not sinned, cast the first stone". Do you know anyone who meets that standard?
As for him being 71.....so am I. Study to gain knowledge, knowledge to gain wisdom, wisdom to gain understanding. All takes time. He has seen more change in his lifetime and adjusted to it, and often helped implement it, than most younger people can imagine. Sorry, the younger generation did not invent change. Change is life. Someday you will be 71 but until then don't presume so much.