Back to John 3:16, "Whoseover BELIEVES in Him", that is Jesus Christ, will be SAVED. Can you not grasp this simple Truth?
I understand what the verse says. What I tried to do is help you see another truth that is as equally important.
You want to argue that the doctrine of election isn't true because of verses like John 3:16, which strongly suggest that we are saved on the basis of our freewill choice. That is, salvation is not offered exclusively to the elect; salvation is granted freely to whoever wants it. And Jesus didn't die for the elect only, he died for each and every person on earth. I get that. But your point is incomplete.
What we are failing to help you see is that freewill choices are not arbitrary. When I make a freewill choice, my selection must reflect who I am as a person. It has to reflect my likes, or dislikes, preferences, wishes, hopes, dreams, values, motives etc. If my choice reflects something about me, then I can truly count the choice as mine. I own it.
Now, let's return to Paul's conversion experience and ask whether Paul's choice to follow Jesus was a freewill choice that he could own for himself. I think a review of the relevant passages will reveal that Saul's choice to follow Jesus didn't happen until Saul became Paul.
Saul was killing Christians and hated Jesus when Jesus knocked him off his horse. Jesus revealed himself to Saul in a vision, challenging Saul's preconceived notions about Jesus' identity. Then Jesus blinded Saul, causing Saul to be led away to stay with Ananias. Saul remained blind for three days. In all that time Saul was unable to freely choose to believe in Jesus or accept him as savior.
We don't know what happened to Saul internally, but we can speculate based on our own personal experience. Saul struggled for three days to make sense of his vision and what impact it had on his belief system. He probably had difficulty sleeping as he attempted, at first to deny what happened, then to explain it away, then finally to accept it. After the third night, he woke up the next day at peace with the idea that he had been wrong about Jesus the entire time and resolved to learn more. So he spent 14 years reading and studying the scriptures.
After reading the testimony of other believers, this sounds fairly typical. Genuine conversion is not merely giving mental assent to an idea; genuine conversion is a transformative, spiritual experience some people describe as a blind man regaining his sight. And immediately one can not believe why others can't see what he can see and he wants everyone to hear the good news. After awhile, as he settles down into a normal routine, he begins a long journey of Bible study in order to achieve a more complete knowledge of the Lord.
The fact is, when Saul experienced the miracle of salvation, his name was changed from Saul to Paul, reflecting his new identity in Christ. Saul the murderer became Paul the apostle of Jesus Christ. He was a new person. He wasn't the same man who persecuted Jesus and his followers. He dedicated the rest of his life to serving them instead.
So then, "whosoever believes" in Jesus are those whom the Father has blessed with a new heart, a new enlightened perspective, a new set of commitments, a new orientation, a new set of motives, etc. The basis of our salvation is Jesus Christ, but our acceptance of the truth is a miracle of the Holy Spirit.