to dare: to bring oneself to do something in the face of fear, danger, or restraint
At its core this word describes summoning the nerve to act when something inside you, whether fear, danger, awe, or a sense of what is proper, would hold you back. The plain English "dare" fits almost every use: someone either brings themselves to do a thing or does not.
What colors the word is context, not a change in meaning. The very same verb can praise or blame. When Joseph of Arimathea steps forward to ask Pilate for the body of Jesus, it is admirable courage. When people repeatedly "did not dare" to question Jesus, it marks how his answers had silenced them. And when Paul asks whether a believer would "dare" to drag a fellow Christian before pagan judges, the same word turns into a rebuke, closer to "have the nerve" or "presume."
Because it so often appears with a negative in the Gospels ("no one dared"), the word frequently measures how much fear or reverence a situation produced. In Paul's letters it more often turns positive, describing the confidence to speak or act for the gospel, sitting close to the inner boldness of θαρρέω and the frank open speech of παρρησιάζομαι.