If a person objectively takes the time to think through the discussion on eternal torment verses annihilation, then he or she will have to conclude that the latter view is a practically inadequate theory on how God punishes the unrepentant and unbelieving. If the wrath of God is satisfied, then why should He destroy the soul of the sinner in the first place? If a person has served his or her due sentence, then would that not imply that he or she is justified? If the wrath of God has not been satisfied, then why should He put an end to the designated punishment? You cannot punish something that does not exist.
There is much more to being a Christian than merely escaping from the wrath of God. That is an infinitesimal aspect as one considers the entirety of the Christian walk. The Christian religion is not merely a code of ethics. Conversion marks the beginning of our relationship with God. As regarding the immortality of the human soul, only God is eternal in the sense that He is uncreated and self-sufficient. Our souls continue to thrive for the reason that they are sustained by the power of God.