1 John 5:9-13
If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.
He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.
And this is the record, that God hath given to us eternal life, and this life is in his Son.
He that hath the Son hath life; and he that hath not the Son of God hath not life.
These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
Present tense, and you don't have to wait for it or wonder about it. And if you say that you HAVE eternal life, then lose it, then you never HAD ETERNAL Life. Hence, you either have it, or you don't. Just like the above verses teach.
Judas Iscariot was originally called one of the 12, cannot tell me that he wasn't saved. But if this happens:
Romans 1:27-32
27 And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.
28 And even as they
did not like to retain God in their knowledge,
God gave them over to a
reprobate mind (The word "reprobate" means "to reject" or "to cast away."
), to do those things which are not convenient;
29 Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers,
30 Backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents,
31 Without understanding, covenantbreakers, without natural affection, implacable, unmerciful:
32 Who knowing the judgment of God, that they which commit such things are worthy of death, not only do the same, but have pleasure in them that do them.
They are lost.