Mark 9:50

Salt is good] 'Divine grace is good, but if the divine grace given to you as Christians dies, owing to your neglect to use it, how will you revive it? Preserve and make due use of the divine grace given to you, especially the grace of charity, and thus you will be at peace with one another.' In Matthew 5:13, by an easy transference, the apostles themselves are called 'salt,' as possessing divine grace. Among the ancients salt was an emblem of wisdom and of friendship. To the latter signification our Lord alludes when He says, 'Have peace one with another.'