1 John 5:13 13 I write these things to you who believe in the name of the Son of God that you may know that you have eternal life.
So who's wrong here? You? Or the Apostle John and the Holy Spirit?
The fact that you still havent learned that is proof that you left because of what St. Jerome called ignorance.
Who cares what Jerome had to say on the matter? Who's he anyway?
St. John did not say you WILL or SHALL eternal life. He said you MAY or MIGHT have eternal life. You need to ask yourself why that is a conditional statement.