Sphódra (σφόδρα) means exceedingly, very much, greatly. It intensifies emotions, reactions, and states — both positive and negative throughout the NT.
The word captures extreme human responses to divine encounters. Matthew 2:10: the Magi 'exceedingly rejoiced' at the star. Matthew 17:6: at the Transfiguration, disciples were 'exceedingly afraid.' Matthew 26:22: at the Last Supper, they were 'exceedingly sorrowful.' Mark 16:4: the stone was 'exceedingly great.' Encounters with God produce extreme reactions — not mild, measured religious feeling but overwhelming joy, trembling fear, and deep sorrow. Authentic faith is not lukewarm (Revelation 3:16).