It actually means a bit more than that.
The point though is it isn't the character's benefit, it is for the benefit of all. Using the powers God gave you to prove that the fleeting martial abilities will not spare you from the power of the faithful.
Roll well enough on your persuasion, and some inquisitors(crazies that they are) might even throw in a few buffs of their own to help you prove to unbelievers the power of God's chosen. Heck, with some Zen level persuasion just about anything you choose to do is "Well, he had no other choice."
Seconded. I can't see being a Saint as a simple "I can use my supernatural powers sometimes to benefit people" but more of a "I'm a really good guy, devoted Christian and will use my powers to prove the awesome power that God has given me!"... and that is ok
Using powers in that way would only prove how awesome the power of God is, and given that the Empress has allowed people to proclaim themselves Atheists, a little "By the power of God, I smite thee!" could help prove a few points. Also, a little persuasion would go a long way with the Inquisition
I'd say it isn't too far fetched a plan, but others may disagree and just read it as written - can use powers sometimes - and that is ok as well... would keep a bit of balance
Then again... a tournament with lvl 8 people... heh... the earth would shake and the skies would part