For Paul, sound doctrine is more than truth propositions; they are ideas that lead to proper Christian activity.
That’s the thing about real faith: it’s not a feeling – it’s an action. Of course there are emotions associated with it – apprehension, exhilaration, anticipation. But the bottom line is that faith is not real if it does not produce results.
You probably haven’t ever been whipped or imprisoned for your faith. But we all share in weaknesses.
But put us in a situation that’s outside of our spiritually safe comfort zone and we wilt. In those circumstances, our “faith” might cost us something.