I never doubted her sincerity in bringing the truth to the American people.

There is no reason to doubt Obama's sincerity about climate change.

It was hard to doubt his sincerity; he'd never called me dude before.

Few who know Miller doubt his sincerity, although it has been suggested that he might simply be trying to make a point.

But don't give me any reason to doubt your sincerity.

My parents tell me they're fine, and I don't doubt their sincerity.

I do not doubt the pope's sincerity in doing good as he sees it.

"The problem in the past was that many of us doubted his sincerity."

Though you know she's right to doubt their sincerity, what would have happened if one of them were sincere?

I don't doubt your friend's sincerity - but as he's 80 the brutal truth is you might find yourself looking after him!