GOT ETERNAL LIFE?
"For God so loved the world that He gave His one and only Son [Jesus Christ] that whoever believes in Him should not perish but have everlasting life." [Jn 3:16]
"Whoever believes" = lit., whoever is one who is a believer. i.e., one who expresses a single moment of faith alone in Christ alone being given (on the cross) for you (your sins).
"Should not perish" = one who believes in the Son immediately enters a state of never perishing (completed action verb).
"But have everlasting life" = the believer immediately begins possession (pres. tense verb) of everlasting life, FOREVER - no matter what (since it is everlasting in duration and depends solely on the promise of God).
FAITH ALONE IN JESUS CHRIST ALONE UNTO ETERNAL LIFE FOREVER!!!