This parable depicts the consequences of these two classes of people about whom we have just discussed. According to Matthew 5.13 ("Ye are the salt of the earth"), salt here in Luke must point to the Christian.
"Salt therefore is good: but if even the salt have lost its savor, wherewith shall it be seasoned?" (v.34)—Salt is good, for it is profitable to men. "Savor" speaks of being set apart and sanctified. What is of tremendous importance to a Christian is to be separated from the world. If salt has lost its savor, how can it be seasoned again? For example, a man buys a piece of fresh meat and thinks of seasoning it with salt. If there is no salt, what can he do to make the meat salty? Or if the salt itself has lost its salty savor, how can he make salty meat?
"It is fit neither for the land nor for the dunghill: men cast it out" (v.35a). This verse speaks of the consequence of our losing our Christian savor, even losing our separation from the world.
"Land" represents the kingdom. To place a savorless Christian in the kingdom of God is most unfit.
"Dunghill" is a defiled and unclean place, and hence suggests hell or the lake of fire. To put a Christian who has lost his savor into hell is equally unfit, for he is already saved.
"Cast it out"—Since he is unfit for either the kingdom or for hell, he must be cast out; that is to say, he must be cast out from the glory of the kingdom.
"He that hath ears to hear, let him hear" (v.35b). This is a word of warning. Anything which causes us to be disjointed from Christ causes us to lose our proper savor. Savor is strength, savorlessness is weakness. How very serious is this matter! We must not love the world. We must instead love the Lord—and with our whole heart. Otherwise, we will have no part in the kingdom. The question is not how much have I done, but am I on the altar. Let us consecrate ourselves to the Lord today, for it will be too late when that day (the day of His coming) arrives.
All three parables inform us of the life of a believer who does not lose his soul today. The reason for not spending all the funds to build a tower, for not mobilizing all the forces to fight a battle, and for becoming savorless salt through mingling with the world is the love of one’s own soul, is a not being willing to let self suffer or to forsake the loveliness of the world. To such a person as this, the glory of the future kingdom is only dimly seen because he cares only for the present moment. Were he willing to deny the demands of his own soul by denying himself, taking up the cross and doing the will of God, it would not be hard for him to build or fight, to hate his father, mother, wife, children, brothers, sisters, and even his own life, and to be separated wholly from the world to become salt with savor. If in this age we do not lose our soul but instead do what we like, or if our consecration is imperfect, we will be cast out during the kingdom time and be mocked as having failed in discipleship.