Do We Have an Eternal Soul?

I frequently hear Christians say, 'We have an eternal soul!'

But is that a) Greek philosophy or b) biblical teaching?

It is mainly the former, and we have read it into our Bibles, a process called eisegesis (as opposed to exegesis - reading out what is there). There is no clear teaching in the Bible on this issue. Nor is there clear teaching that humans are tripartite in nature: body, soul and spirit. Grudem quotes Berkhof:

'The tripartite conception of man originated in Greek philosophy, which conceived of the relation of the body and the spirit of man to teach other after the analogy of the mutual relation between the material universe and God.' Grudem, Systematic Theology, p481

The fact that the Hebrew word nephesh is often translated 'soul' does not help. In fact it should be translated something like 'inner being' or 'life-breath'. Though there are some verses that talk about a dead nephesh - i.e. a corpse (Lev 21:11; Num 6:6). Also animals have nephesh (Gen 1:20).

The Hebrew term ruakh is used for both 'wind' and 'spirit' (Gen 1:2; Isa 7:2). The term is used less frequently than nephesh, and is more likely refer to God's Spirit than to human spirit, per se. The prophets were filled with the Spirit, or the Spirit came on them (there are many verbs used for this).

In the New Testament a) the Spirit is available to all (young, old, men, women) b) Jesus teaches us that the result of believing and following him is that we inherit eternal life. This is our Christian hope. We therefore do not need to resort to the Greek philosophical tradition of us having an eternal soul. What, exactly, happens to us when we die is hard to figure out (from the Bible, from philosophical studies, etc.), but we do know that we will be with him for all eternity. Let's take comfort in that truth.

For further reading: http://ntwrightpage.com/2016/07/12/mind-spirit-soul-and-body/

And watching: https://youtu.be/g_igCcWAMAM

For the biblical scholars I have included a quote from NIDOTTE on nephesh below:

Nephesh:

OT 1. Comparable roots in Ugar. and Akk. confirm the basic biblical meaning for נֶפֶשׁ to be “breath” (as do the three verbal instances, Exod 23:12; 31:17; 2 Sam 16:14). Care should be taken not to import a Greek paradigm of psychology to נֶפֶשׁ; though at times in its over 700 appearances it refers to the inner person, it seldom denotes a “soul” in any full sense. Initially, it means the literal breath of both animals (Gen 1:20–30; 7:22, נְשָׁמָה) and humans (2:7; Ps 107:5; 1 Kgs 17:17, נְשָׁמָה). Since breath is tantamount to life itself, נֶפֶשׁ essentially means “life” on numerous occasions, e.g., Gen 9:5, “I will require the נֶפֶשׁ of man;” (also 2 Sam 23:17). The relationship of breath and life is taken a semantic step farther when נֶפֶשׁ is used to denote the living being itself, e.g., Lev 4:2, “If a person (נֶפֶשׁ) sins …” (Josh 11:14, נְשָׁמָה). In this sense נֶפֶשׁ becomes a synecdoche, representing the total person, both one’s physical and nonphysical composition. In fact, נֶפֶשׁ is so identified with the whole person that ironically it can denote a nonbreathing corpse! (e.g., Lev 21:11 “nor shall he approach any dead נֶפֶשׁ.”). This identity of נֶפֶשׁ with the entire person gives the word its frequent function as a reference to the self, e.g., Ps 7:2 [3], “or they will tear me (my נֶפֶשׁ) like a lion”; Lev 26:11, “I (my נֶפֶשׁ) will not abhor you.”

2. In some cases נֶפֶשׁ stands for the inner person rather than the entire individual. נֶפֶשׁ represents the desires and inclinations of animals and humans. Perhaps the panting breath that is associated with intense desire is the reason for this nuance in נֶפֶשׁ (see other words in this semantic group used for “panting” [שָׁאַף, פּוּחַ]). These desires range from the sexual drive of a wild donkey in heat (Jer 2:24), to the physical appetite (Prov 23:2; Eccl 6:7), to the holy preferences of those who love God with all their “heart … נֶפֶשׁ and … strength” (Deut 6:5). Even Sheol has an appetite for the wicked (Isa 5:14; Hab 2:5), as the wicked do for the righteous, e.g., Ps 27:12, “Do not turn me over to the נֶפֶשׁ of my foes.” One’s נֶפֶשׁ can be angry or bitter (Judg 18:25; Prov 14:10; Isa 19:10; Ezek 25:6), yet fortunately it can be encouraged as well (Ps 86:4).

VanGemeren, Willem, ed., New International Dictionary of Old Testament Theology & Exegesis (Grand Rapids, MI: Zondervan Publishing House, 1997), 133