'Fragrance' in the Bible

Mary took a litron of very expensive perfume made of pure nard and anointed Jesus' feet. She wiped his feet with her hair, and the house became filled with the fragrance of the perfume.

But thanks be to God! He always leads us triumphantly by the Messiah and through us spreads everywhere the fragrance of knowing him.

To some people we are a deadly fragrance, while to others we are a living fragrance. Who is qualified for this?