Tercüme - İngilizce-Portekizce - The heart that prays to God is afraid of nothing

"ko-u" is a verb that means literally to "ask (someone) (for something)," to "request (something) (from someone)."
It is not often used colloquially and so has a bit of a literary quality. I therefore translated it here according to the context as "prays." The context leaves it open just what this heart asks God for, i.e. probably strength or courage or such like...