"the strength of his convictions"

I'm a little confused by the phrase "he has the strength of his convictions". Does it mean that a person has strong convictions, or does it mean that a person is given strength through having convictions?

Is this a phrase that is sometimes misapplied?

Thanks.

Patty

I couldn't find anything in my references. So I'm just going to wing it. This is my opinion/guess. I believe the phrase means that a person acts on the strength of his convictions. Practices what she preaches. Doesn't just "talk the talk" -- but also "walks the walk." Transforms beliefs into actions.

And here's a prayer along those lines:

The things, good Lord
that we pray for;
Give us the strength to work for.
(Sir Thomas More. 1478-1535)