There is a well-known saying attributed to St. Augustine; ‘In essentials, unity; in non-essentials, liberty; in all things, charity’.
In the context of Christian theology this usually means that we should not argue about or divide over the non-essential doctrines of the Faith. Most scholars agree with this but the problem is that relatively minor doctrines have profound implications. Take for instance the doctrine of the essential nature of man.
Many modern theological thinkers reject the view that a person is anything other than a unity (monism) because they can find no scientific evidence for a spirit/soul. They claim that the idea that humans have more than one constituent part is the product of ancient Greek philosophy. They believe that the theology of the Old Testament supports their view and they also argue that any attempt to describe humans as other than a unity leads to an unbiblollical depreciation of the body.
This understanding of the human being has some serious implications. For instance, in terms of this view, when a person dies then they simply cease to exist. Either life ends at the grave or is suspended in some sort of ‘soul sleep’ until the great resurrection at the end of time. It is hard to differentiate, in terms of monism, just how a human differs from an animal, and it requires us to perform mental gymnastics with several biblical texts. For instance Jesus told the thief on that cross that “today you will be with me in paradise.” (Lk 23:43) and Paul wrote that he would prefer to be away from the body and at home with the Lord (2 Cor 5:8)
There are two other current views on this doctrine. The most common among reformed and conservative evangelical theologians is Dichotomism. This view has dominated academic thinking on this subject since the Counsel of Constantinople in AD 381. The idea here is that the human being is composed of two basic parts, a material and an immaterial. The non-material part is interchangeably called spirit or soul, or in more modern thinking, mind. If there is a distinction, they say, it is that the word ‘spirit’ describes the human capacity to relate to God while ‘soul’ describes the capacity to relate to self and others. The main biblical basis for this view is the fact that the words spirit and soul are used interchangeably in many places in the Bible (Gen 35:18; Eccl 12:7; Heb 12:23; Rev 6:9 and so on).
There is a third way of viewing the human makeup which is still popular in Pentecostal and charismatic circles. It is called Trichotomy and it was taught by the early church fathers prior to late 4th century. Trichotomism is the belief that we are made up of body, soul, and spirit. Whilst humans are functionally unitary beings we do have both physical and immaterial dimensions. The non-physical aspect is in turn made up of a soul and a spirit. Soul describes elements such as mind, emotion, memory, will and so on. Spirit describes that aspect of our being that communicates with God and interfaces with the spiritual realm. The soul is generated by the brain but when the body dies it continues to live on in association with the spirit. This continued existence is either apart from God or in relationship with Him. When a person is born again their spirit comes alive to God; if they are not born again the spirit continues to be separated from the life of God.
So, relatively minor doctrines are still important for they have profound implications. It is true that we should not divide over them but we certainly should debate them and consider them very carefully.