If the atheist does not change his ways, acknowledge his own disobedience toward his Creator, and ask God for forgiveness, he can expect to spend forever in the Lake of Fire (Revelation 21:8; cf Luke 12:46; Hebrews 11:6; Galatians 3:22; John 1:12, 3:3, 3:18, 8:24, 20:31; Acts 16:31; Romans 10:9; 1 Corinthians 1:21; 1 Corinthians 6:9-10; Revelation 20:15).
We owe our lives to our Creator. But we don't give Him His due.
Some people claim we can make it up to Him by paying Him back later, through good deeds or something like that.
But this is impossible. The math doesn't add up.
Other people, known as "atheists", try to get out of the problem by pretending God doesn't exist (Romans 1:21). In so doing, they deny all possibility of rational thought.
The Christian, like everyone else, recognizes that there is a God, that he ought to obey God, that he does not obey God, and that this is a problem.
The Christian, unlike everyone else, puts His trust solely and completely in God to resolve this problem (Acts 2:21; Hebrews 11:6; Romans 4:3; Isaiah 26:4).
The Christian rejoices to hear the good news of how God has resolved the problem of our sin. Our debt has been paid by One who had no debt! As God the Son, Christ, unlike us, does not owe His life to anyone. He has the moral justification to do whatever He wants with it.
And He has decided to sacrificially spend His eternal life obeying my Creator, paying my debt, in my place! (Philippians 2:6-8; Colossians 2:14)
What an amazing friend!
May God draw you to Himself through Jesus, His Son.