“… men do lose their power of savouring others with righteousness when they are willing to place their eternal welfare in jeopardy for the sake of any temporal advantage.”

The Lesson is taken from the Holy Gospel according to Matthew

Matt 5:13-19
At that time: Jesus said unto his disciples: Ye are the salt of the earth: But if the salt have lost his savour, wherewith shall it be salted? And so on, and that which followeth.

Homily by St. Augustine the Bishop (of Hippo)
Book 1 of the Lord's Sermon on the Mount, ch. 6, vol. 4
The Lord would have us understand how that men do lose their power of savouring others with righteousness when they are willing to place their eternal welfare in jeopardy for the sake of any temporal advantage, like as attainment of ease or luxury, or escape from suffering or toil. For that which is eternal, unlike things of this world, can neither be bestowed by men, nor by them taken away. Hence, when he asketh: If the salt have lost his savour, wherewith shall it be salted? he would have us understand the question to be: If ye, by whom mankind is preserved from corruption, be willing to lose the kingdom of heaven so as to escape trials or persecutions in this world, who is there to preserve you from corruption, seeing ye are they that God hath chosen to preserve all others from corruption?

Those that should be the salt of the earth, but have lost their savour, are thenceforth good for nothing, but to be cast out, and to be trodden under foot of men. But no one that suffereth persecution is truly said to be trodden under foot of men. Rather, that one is truly trodden under foot of men who through fear of persecution hath lost the savour of righteousness. For no one can be trodden upon, unless he be beneath him which treadeth upon him. And certainly no one who hath his heart in heaven, no matter how grievously he doth suffer in his body on earth, is rightly said to be beneath anyone who misuseth him.

(Photo credit: Our Daily Bread)