You said — “I believe Thompson is a Christian because he has done what the Bible says is necessary to become a brother in Christ.”
The trouble is that he doesn’t know what the Gospel or the “good news” is... If one doesn’t know what the Gospel is, one cannot choose to become a Christian. One cannot choose what they do not know. It’s that simple.
Regards,
Star Traveler
Fred knows the Gospel. Fred knows Jesus. Fred is a Christian. He’s not perfect. But neither were the Apostles. Peter went so far as to deny knowing Jesus three times, and look what he did not long thereafter.
God chose Fred a long time ago. And Fred answered God’s call.