Thematic Bible: Who is the salt of the earth

And seeing the multitudes He went up to a mountain, and when He was set down, His disciples came to Him, and He opened his mouth and taught them, saying, Blessed are the poor in spirit; for theirs is the kingdom of heaven. read more.
Blessed are they that mourn; for they shall be comforted. Blessed are the meek; for they shall inherit the earth. Blessed are they that hunger and thirst after righteousness; for they shall be satisfied. Blessed are the merciful; for they shall obtain mercy. Blessed are the pure in heart; for they shall see God. Blessed are the peace-makers; for they shall be called the children of God. Blessed are they, who are persecuted for righteousness sake; for theirs is the kingdom of heaven. Blessed are ye when men shall revile and persecute you, and utter all manner of reproach against you falsly, for my sake: rejoice and be exceeding glad; for great will be your reward in heaven: for so they persecuted the prophets, that were before you. Ye are the salt of the earth, but if the salt be grown insipid, wherewith shall it be seasoned? it is no longer fit for any thing, but to be thrown out of doors, and trodden under foot.