You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot by people. (Matthew 5:13)

The word of the Lord came to me: “Son of man, how is the wood of a vine different from that of a branch from any of the trees in the forest? Is wood ever taken from it to make anything useful? Do they make pegs from it to hang things on? And after it is thrown on the fire as fuel and the fire burns both ends and chars the middle, is it then useful for anything? If it was not useful for anything when it was whole, how much less can it be made into something useful when the fire has burned it and it is charred? (Ezekiel 15:1-5)

I am the true vine, and My Father is the vinedresser. Every branch in Me that does not bear fruit, He takes away; and every branch that bears fruit, He prunes it so that it may bear more fruit. You are already clean because of the word which I have spoken to you. Remain in Me, and I in you. Just as the branch cannot bear fruit of itself but must remain in the vine, so neither can you unless you remain in Me. I am the vine, you are the branches; the one who remains in Me, and I in him bears much fruit, for apart from Me you can do nothing. (John 15:1-5)

I will make the land desolate because they have been unfaithful, declares the Sovereign Lord. (Ezekiel 15:8)

God cuts down the unfruitful vine (Israel) and throws it into fire because she has been unfaithful. Saints are united with Christ through the Holy Spirit. Those who have not received the Spirit cannot bear fruit (faith). They will be thrown into fire on the Day of the Lord. Apostle Paul talks about the fruit of the Holy Spirit in his letter to the Galatians.

But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law. (Galatians 5:22-23)

Many interpret these verses from a moral point of view. But the distinctive feature of a good vine is faith in God. Faith is the gift from God (Ephesians 2:8).

Many Christians think science is against God. But science, when used and understood properly, is beneficial in understanding the Bible. I looked up some information on salt. Salt cannot lose saltiness as long as it is in natural form. But it can lose saltiness when it contains additives. Salt in pure form does what it should do – enhancing the taste of food and preventing bacterial growth. When its natural form is broken, it goes bad. It becomes rubbish. It loses its saltiness and cannot suppress bacterial growth. So is the vine that cannot bear fruit. A vine is useful as long as it bears good fruit. Saints cannot survive unless we remain in God and His words.

If we add anything to the pure form of faith like those who follow Pelagianism and Semi-Pelagianism, we are no longer called Christians by God. True Christians are the light of the world because we know God and have faith in Him, not by our will, but by God’s.