What, if anything, is the difference in these two terms?  Is man composed of two parts (the outward man, i.e., the human body; The inward man, i.e. spirit or soul – these words being used interchangeably)?  Or, is man composed of three parts (the outward man, i.e. the human body; the inward man composed of two distinct parts – the soul and spirit)?

Soul

The Old Testament term is ‘nephesh.’  This is the Hebrew word translated ‘soul’ (one of 28 English words by which the KJV translated this word).  The word has a variety of usages depending upon the context.  It is used of: (1) animal or physical life – see Genesis 1:20 (life); Genesis 1:21, 24 (living creature); Genesis 1:30 (life); Genesis 2:7 (soul); (2) It is sometimes used of persons (Genesis 36:6) even if dead (Leviticus 21:1, 11).  (3) God is said to have a ‘nephesh’ Jeremiah 51:14 (Himself); Amos 6:8 (Himself); Psalm 11:5 (soul); Job 23:13 (soul).  Robert Morey has well observed, “In no way can God’s nephesh be reduced to the principle of physical life, because God does not have a physical body (Death and Afterlife, p. 46).  (4) There are places in scripture where the nephesh is distinguished from the physical life – 2 Samuel 11:11; Isaiah 1:14.  (5) The soul is said to worship God, Deuteronomy 10:12; sorrow, Leviticus 26:16; feel bitterness, 1 Samuel 1:10; experience misery, Judges 10:16.  Also grief, 1 Samuel 2:23; The soul can pant and thirst after God, Psalm 42:1-2).

The New Testament term is ‘psuche.’  (The Septuagint Greek translation also used this word as the equivalent of the Hebrew ‘nephesh’).  This word occurs more than 100 times in the New Testament.  It is rendered by the KJV into six English words.  Most frequently it is translated ‘soul’.  The word ‘psuche,’ like ‘nephesh’, is used in several different ways.  It is used of: (1) physical life (Matthew 2:20; Matthew 6:25; Mark 3:4; Mark 10:45; John 10:11, 15 – all rendered ‘life.’  (2) It is used for people in general (Acts 2:41).  (3) It is used of God (Matthew 12:18; Hebrews 10:38).  Robert Morey has written, “That ‘psuche’ cannot mean physical life when used of God is obvious.  It is used to refer to the seat of emotion, intellect, and will in God” (ibid, p. 55).  (4) It is used of disincarnate souls that worship at God’s throne (Revelation 6:9).  (5)  It is used of the part of man that goes to hades (Acts 2:26-27).  (6) It, at times, is viewed as distinct from the body or physical life (Matthew 10:28; 3 John 2).  (7) It refers to man’s will (Ephesians 6:6 – heart); man’s emotions (Matthew 26:38); and man’s intellect (Acts 14:2 – ‘minds’).  It is closely connected with the heart (Acts 4:32).  (8) It also at times refers to animal life (Revelation 8:9; Revelation 16:3 – rendered ‘life’ and ‘soul’).

Spirit

The Old Testament Hebrew for spirit is ‘rauch.’  Morey writes, “The word ‘ruach’, like ‘nephesh’ has a wide range of meanings.  First, it seems originally to have referred to the wind which was viewed as being invisible and immaterial (Genesis 8:1).  Second, since God is invisible and immaterial, like the wind, He is described as ‘spirit’ (Isaiah 63:16).  Third,  since angels of God are invisible and immaterial, the are called ‘spirits’ (Psalm 104:4, KJV; cf. Hebrews 1:14).  Fourth, since the life principle which animates man and animal is invisible and immaterial, it is also called ‘spirit’ (Genesis 7:22).  In this sense it was viewed as the ‘breath’ of life which departs at death.  Fifth, since man has an invisible and immaterial self or soul which transcends the life principle by its self-consciousness, man’s ‘mind’ or ‘heart’ is called his ‘spirit’ (Psalm 77:6; Proverbs 29:11, KJV).  The invisible side of man which is called ‘spirit’ cannot be reduced to the mere principle of physical life or of the breath of the body because man’s transcendant self is contrasted to those things in such places as Isaiah 42:5.  Also, man’s self-awareness as a cognitive ego obviously transcends the life principle which operates in animals.   At death this transcendent ego or disincarnate mind is called a ‘spirit’ or a ‘ghost’ (Job 4:15).  Sixth, since attitudes and dispositions such as pride, humility, joy, or sorrow are invisible and immaterial, they are described as being someone’s spirit – Proverbs 11:13; 16:18 (ibid, p. 51-53).

The New Testament greek term for ‘spirit’ is ‘pneuma’.  (The Septuagint Greek translation used this work as an equivalent to the Hebrew ‘ruach’).  Morey indicates that this word refers to “First… wind…”  John 3:8.  Second, ‘pneuma’ refers to the life principle which animates the body (Revelation 13:15).  Third, ‘pneuma’ is used to describe the immaterial nature of God and angels (John 4:24; Hebrews 1:14).  Christ defined a ‘spirit’ or ‘ghost’ as an immaterial being (Luke 24:39).  Fourth, ‘pneuma’ refers to the disposition which characterizes a person, such as pride, humility, fear, etc. (1 Peter 3:4).  Fifth, ‘pneuma’ is used to describe the disincarnate spirit or soul of man after death (Matthew 27:50; Luke 24:37, 39; John 19:30; Acts 7:59; Hebrews 12:23; 1 Peter 3:19).  Sixth, man’s transcendent self, or ego, is also called ‘pneuma’ because of its immaterial and invisible nature (1 Corinthians 2:11).  It is described as the center of man’s emotions, intellect and will (Mark 8:12; Mark 2:8; Matthew 26:41).  Since man’s ‘pneuma’ transcends his mere physical life, it is frequently contrasted to his body (Matthew 26:41; Mark 14:38; Luke 24:39; John 3:6; 6:63; 1 Corinthians 5:5; 7:34; 2 Corinthians 7:1; Galatians 5:17; 6:8, 9; James 2:26).  It is man’s ‘pneuma’ which ascends to God at death – Acts 7:59 (ibid, p. 61-62).

Synonymous?

At times the Bible uses the term ‘spirit’ and ‘soul’ interchangeably, (see Isaiah 26:9; Luke 1:46-47) though the terms are not synonymous.  The term ‘spirit’ as to do with the invisible or immaterial.  The term ‘soul’ has to do with life or being.

At times the words are used with distinction one from another (e.g. Hebrews 4:12; 1 Thessalonians 5:23).  Bert Thompson has written, “The word ‘spirit’ sometimes refers to wind or air (Genesis 3:8; John 3:8), the word ‘soul’ does not.  The word ‘spirit’ refers to demons (Mark 5:2; Luke 9:39); the word ‘soul’ does not.  The word ‘soul’ sometimes refers to both the inner and outer man (i.e. the whole person, Exodus 1:5; Ezekiel 18:20; Acts 2:41; Romans 13:1).  The word ‘spirit’  does not.  The word ‘soul’ sometimes refers to a corpse (Numbers 5:2; 6:6; Psalm 16:10; Acts 2:27).  The word ‘spirit’ does not” (Rock Solid Faith: How to Sustain It, p. 187-188).

The context must determine the meaning of the usage of the words.  Bert Thompson illustrates, “…were I to ask you to define the term ‘foil’ without seeing the word in context you could not possibly know what I meant.  I might be referring to: (1) a noun used to define a fencing sword; (2) a noun that indicates a thin, shiny metal used by cooks in kitchens all over the world; or (3) a verb used as a synonym for defeat (ibid, p. 174-175).  Even so, the terms ‘spirit’ and ‘soul’ must be understood from context.

In Hebrews 4:12, the terms are used with distinction one from another.  Just a marrow is within joints or bony matter; Even so, the term ‘spirit’ seems to refer here to the inner man and the term ‘soul’ to the outer man.

In 1 Thessalonians 5:23, again the terms are used with distinction, in some way.  Some think that this teaches that man is a three-fold being – body, spirit and soul.  Others such as Adam Clark have another explanation.  He understood the term ‘body’ to refer to our material bodies; The term ‘soul’, he understood to refer to man’s affections, passions, and emotions; And, the term ‘spirit’ to refer to ‘the immortal spirit’ (vol. 6, p. 555).

Some Things Certain

The Bible clearly indicates that there is an outward man, and there is an inward man (2 Corinthians 4:16-5:1; Romans 7:22; Ephesians 3:16; 1 Peter 3:1-6).  There is an existence ‘in the flesh’ as well as without (Philippians 1:21-24).  One can be conscious outside the body (2 Corinthians 12:2-4).  There is a part of man that survives the body (Matthew 10:28).  The physical body is viewed by Peter as a tent.  Listen to Peter, “Yea, I think it meet, as long as I am in this tabernacle (tent – B.H.) to stir you up by putting you in remembrance (2 Peter 1:13).  Think through this: If Peter was in a tabernacle (tent – ref. to physical body), then the tent must not be Peter.  Something dwells in a tent.  In this context Peter refers to the real substantive self.  There is a conscious existence on the other side (Luke 16:19-31).  Read John 16:17-18.  Even on the other side Christ had the power to take His life again.  Yet, He was in hades.  Thus, hades will be a place of consciousness.  Is it well with your soul?  Where will your spirit go after death?  All of us will be somewhere forever!