Each of the three parts is defined as a person. It remains somewhat mysterious as to just what this means.¹ Are the persons really human in form? Or do created human beings resemble the three holy persons of the Trinity?
According to one interpretation of the view that created human beings resemble the three holy persons of the Trinity, some individuals predominantly act as God’s hands, others as God’s mind, others as God’s heart and so on. Biblical support for this idea is often cited in Romans 12:4-6, 1 Corinthians 10:17, and Collossians 3:15.
The notion of different types of people corresponding to different parts of the Divine Body is found in Emanuel Swedenborg‘s (1688-1772) The Universal Human and Soul-Body Interaction. Swedenborg believed he was further delineating the connection between earthly people and their heavenly counterparts. But it remains unclear whether Swedenborg’s vision was identical to other Christian beliefs.
The belief that different types of people correspond to different parts of the Divine Body is also fundamental to Hinduism, a religion which some scholars say has its own kind of Trinity, one quite different from the Christian Trinity. The Hindu Trinity consists of Brahma (Creator), Visnu (Preserver of the Universe) and Siva (Cosmic Destroyer).
But again, to contend that the Swedenborgian, Hindu and Christian Trinities are identical is a gross simplification.
The idea that the diversity of human beings resembles the Trinity raises important questions about the relationship between God and humanity. For most Christians it does not mean that God is humanity, and nothing more. Rather, the idea is that God, as Creator, is reflected by and present in humanity but still transcends the human condition.
The Christian Holy Trinity is often dismissed as a socio-historical construction, but those claiming to have been granted a vision of the Holy Trinity say that its mysterious character can only be fully comprehended through revelation. Most Christian saints who have experienced a vision of the Trinity say that theological formulas only point the way. True experience of the Trinity apparently unravels the mystery or, perhaps, clarifies it.
Rev. Glenn “Mac” at GlennFrazier.com adds:
Since you mention Swedenborg, it might be worth pointing out that he explicitly spoke up against the idea of a trinity of persons. According to his theology (in, e.g., his book, True Christian Religion), Jehovah the Father and Jesus the Son were not only one God, but also the one and only one person of God. Likewise, the Holy Spirit is the activity of that person, and not a seperate person in its own right. This is somewhat similar to Michael Servetus’ ideas expressed a good deal earlier in his “Errors of the Trinity”. Swedenborg’s idea of a trinity of essentials, rather than of persons, should not be confused with modalism-the idea of there being one God that at various times takes on different functions or modes in sequence. To Swedenborg, the Father was literally God’s soul, the Son his body, and the Spirit his influence/activity, not by analogy, but actually.²
¹Wikipedia further outlines the standard theological wording, but it doesn’t really help much. http://en.wikipedia.org/wiki/Trinity