A litmus test is a test in which a single factor is decisive in proving
the presence or absence of something. "I have eternal life," many
said, as I did, but passing the litmus test determines whether someone
has truly believed as the Scriptures say.
In the last day, that great day of the feast, Jesus stood and cried
out, saying, "If anyone thirsts, let him come to Me and drink. He who
believes in Me, as the Scripture has said, out of his heart will flow
rivers of living water." But this He spoke concerning the Spirit,
whom those believing in Him would receive; for the Holy Spirit was not
yet given, because Jesus was not yet glorified" (John 7:37-39)
Jesus answered and said to her, "If you knew the gift of God, and
who it is who says to you, 'Give Me a drink,' you would have asked
Him, and He would have given you living water (the Holy Spirit)."
...whoever drinks of the water that I will give him shall never thirst;
but the water that I will give him will become in him a well of water
springing up to eternal life." (John 4:10,14)
So how do the scriptures say one must believe in order to have this
river of living water flowing out of him? For the scriptures give us
the litmus test in order that we could know whether we have passed from
death to life and have truly received the Holy Spirit - the Water of
Life. John 5:24 presents the good news in very clear and simple terms:
Most assuredly, I say to you, he who hears My word and believes Him
who sent Me has everlasting life, and shall not come into judgment, but
has passed out of death and into life.
But how does anyone know he is saved? Does he know because the preacher
tells him so? Is it enough to hear, "I know that I know that I know I
am saved"? It wasn't enough for me. I still wasn't sure.
Something very deep seemed to be missing. Then I discovered, well
friends showed me, the marvelous first letter of John. It tells
everyone how they can know. It gives all of us the litmus test. Take it
yourself. Read through 1 John, chapters one through five. Then
especially consider verses 3:14, 16, and 17. They utterly disqualify
mere mental belief (Gnosticism).
14We know that we have passed from death to life, because we love
the brethren. He who does not love his brother abides in death. 16By
this we know love, because He laid down His life for us. And we also
ought to lay down our lives for the brethren. 17But whoever has this
world's goods, and sees his brother in need, and shuts up his heart
from him, how does the love of God abide in him?
(excerpted from "The Litmus Test" at
http://www.thelitmustest.org/litmus-test.html )