Well for this verse specifically, I remind people of what Paul wrote:
1 Thessalonians 5:23
And the very God of peace sanctify you wholly;
and I pray God your whole
spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ.
So a saved man is a trichotomouos being- body, soul and spirit.
An unsaved man is bichotomous - only a body and soul, because of what happened in the garden.
Genesis 2:17
King James Version
17 But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
Now Adam and Eve did not physically die that day but a death did occur. Paul explained it in Ephesians:
Ephesians 2
King James Version
2 And you hath he quickened, who were dead in trespasses and sins;
2 Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience:
3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
4 But God, who is rich in mercy, for his great love wherewith he loved us,
5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;)
So even though we are alive we were dead somehow. that was not physically or soully, but spiritually. Our spirit were dead and when we got saved our spirits were quickened (made alive).
And as Paul said in corinthians:
2 Corinthians 5:6-9
King James Version
6 Therefore we are always confident, knowing that, whilst we are at home in the body, we are absent from the Lord:
7 (For we walk by faith, not by sight:)
8 We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord.
9 Wherefore we labour, that, whether present or absent, we may be accepted of him.
So when we are in our bodies we are away from the Lord. but when we die, our bodies go in th ground but our soul and spirit go to heaven.
I showed you the soul in the Rev. passage, and as for our spirits:
Hebrews 12:23
To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the
spirits of just men made perfect,
This is why I believe in an immortal soul.