All can now their eternal destiny before they die. Lost folk know they refuse to believe the truth and 1 John exists, in part, to comfort Christians with the knowledge of their salvation. Secure in the grip of grace, no fear of condemnation - all who are in Christ Jesus.
Incorrect. One won't know until their particular judgment.
"Wherefore, my dearly beloved, (as you have always obeyed, not as in my presence only but much more now in my absence) with fear and trembling work out your salvation." Philippians 2:12
"Wherefore, he that thinketh himself to stand, let him take heed lest he fall." 1 Corinthians 10:12