My candid answer would be "I do not know. God is the Judge and I am sure He will do what is right." However, no one has sinned just once.If an individuals sins once as in "illustration above" and they die the next day. do they deserve to burn forever.
the candid answer: yes
My own opinion is that the person in Christ who commits a sin just before death is covered by the Grace of God and the blood of The Lamb. We all have sinned in ignorance and failed to confess it.
I do not believe we should develop our doctrine in order to make apologetics to unbelievers more palatable. I sympathize with your frustration in witnessing to unbelievers but Jesus commanded that we not "cast our pearls before swine" (hogs have no use for pearls). There is a point where we must prudently "shake the dust off our sandles" and move on. This may need to mean no more than dropping the subject, praying for God to "open the door", and patiently waiting for opportunity.i am not trying to be ignorant. maybe you can give me an explanation for E.T justification for the "one sin" example that I can share with my atheist and non believing friends. I have failed thus far!
furthermore, I hope my tone doesn't come across to confrontational. its because I am frustrated when confronted with these issues from some atheists individuals that I am friends with. I am undecided on these topics for obvious reasons
On the other hand, we need to be prepared to answer for the hope that is within us.