The Enneagram of Personality is a human personality typology system developed by Oscar Ichazo and his students Claudio Naranjo and Helen Palmer.
It is based on a system which G. I. Gurdjieff claimed he was introduced to by the Sarmoung Brotherhood , an esoteric sect of Sufism (which in turn is a mystical sect of Islam). 
The typology defines nine personality types (“enneatypes”) with proponents claiming that every person fits into one of them.
Each of the nine personality types includes, among other things, virtues and vices as well as basic fears and desires. In addition, each personality type has its own ‘stress’ or ‘security’ factor (sometimes referred to as disintegration and integration points) which indicates which personality type someone may resemble under particularly adverse or particularly favorable conditions.
There are different schools of thought about the typology, but basically the system is used for self-analysis, as well as gaining insight into personal-, family- and workplace relationships.
Once someone identifies his or her personality type he or she can ostensibly learn, still using the enneagram as a guide, how to improve himself, avoid personality clashes, and even grow spiritually.
Use of the Enneagram of Personality has long been popular within Catholic circles, and in recent years it has also started to gain traction among followers of the Emerging Church. 
In A Christian reflection on the “New Age”, the Pontifical Council for Culture and the Pontifical Council for Interreligious Dialogue of the Roman Catholic Church writes:
An adequate Christian discernment of New Age thought and practice cannot fail to recognize that, like second and third century gnosticism, it represents something of a compendium of positions that the Church has identified as heterodox.
John Paul II warns with regard to the “return of ancient gnostic ideas under the guise of the so-called New Age: We cannot delude ourselves that this will lead toward a renewal of religion. It is only a new way of practising gnosticism – that attitude of the spirit that, in the name of a profound knowledge of God, results in distorting His Word and replacing it with purely human words.
Gnosticism never completely abandoned the realm of Christianity. Instead, it has always existed side by side with Christianity, sometimes taking the shape of a philosophical movement, but more often assuming the characteristics of a religion or a para-religion in distinct, if not declared, conflict with all that is essentially Christian”.(6) An example of this can be seen in the enneagram, the nine-type tool for character analysis, which when used as a means of spiritual growth introduces an ambiguity in the doctrine and the life of the Christian faith.
Jesuit priest Fr. Mitchell Pacwa  has researched the enneagram of personality. He points out historical, psychological and theological problems with its theories.
Besides these scientific and psychological problems with the enneagram, Christians have many theological difficulties with it. The frequent use of such occult practices as divination and spiritism in Gurdjieff and Ichazo immediately throws up a red flag. In Deuteronomy 18:9-15 and many other Scripture passages, God our Lord forbids such pursuits. Most of the “experts” I know, however, avoid the occult or know nothing about its presence in the enneagram’s background. Despite this avoidance or ignorance, theological problems appear in enneagram workshops across the country.
Some enneagram experts claim that original sin begins when small children choose their ego type or fixation. This is utter nonsense to the Christian. Original sin, by its nature, is not some wrong that a person commits. Rather, because of the Fall of our first parents, Adam and Eve (in trying to “become like gods” by grasping for forbidden knowledge about good and bad — Gen. 3:5), all humans inherit original sin. Due to the fallenness of human nature, people are prone to commit actual sins, and frequently do so. Identifying a three- or four-year old child’s choice of compulsion with original sin is a biblically false doctrine.
Another theological error follows from this one, namely, humans can undo the effects of this so-called original sin of ego fixation by means of Gurdjieff’s, Ichazo’s, or someone else’s spiritual “work.” Certainly, people can get help from others to overcome psychological problems, and they should seek the wisdom and counsel of solid, Christian psychologists when they need that type of help. However, such “work” can never be the removal of original sin, or any other sin, for that matter. Only the saving death on the Cross of Jesus Christ, true God and true man, can remove our sin. This is a free gift of God’s grace which no human can earn or deserve. We accept this grace from the merciful God and return gratitude to Him, which is itself His gift to us. Any removal of the effects of sin — the psychological residue or ramifications of sin — may be alleviated by psychological help along with other aids, such as charity to the poor, proclaiming the Gospel, and so forth.
Further, the prophet Isaiah wrote that wisdom, understanding, and counsel are gifts of the Holy Spirit (Isa. 11:2), so we should seek psychological help from Christians blessed by these gifts. The Christian should know and proclaim to the world that even psychological techniques require God’s grace if they are to be effective in removing the effects of our sin. Both the forgiveness of our sins and the removal of their effects demand God’s unearned grace in our lives.– Source: Mitchell Pacwa, S.J., Tell Me Who I Am, O Enneagram, Christian Research Journal, Fall 1991, page 14.
In his book Catholics and the New Age: How Good People Are Being Drawn into Jungian Psychology, the Enneagram, and the Age of Aquarius, Pacwa has devoted two chapters to the Enneagram.
The Psychology Wiki says:
Because of differences among teachers in their understanding of the personality characteristics of the nine types and more theoretical aspects of Enneagram dynamics some skeptics argue that more research needs to be done to test the Enneagram as an empirically valid typology.
While some believe that current research does not support the Enneagram’s validity (especially regarding the concepts of Wings and the Stress and Security Points), others believe that because of its complex and ‘spiritual’ nature the Enneagram typology cannot be accurately evaluated by conventional empirical methods.
Many psychologists and scientists regard the Enneagram as a pseudoscience that uses an essentially arbitrary set of personality dimensions to make its characterizations.
Lacking falsifiability, the claims of Enneagram theorists cannot be verified using the empirical scientific method. In this respect it is not considered to be any different from many other typological models such as that of Carl Gustav Jung’s on which the Myers-Briggs Type Indicator is based.
The Pontifical Council for Culture and the Pontifical Council for Interreligious Dialogue of the Roman Catholic Church has also expressed concerns about the Enneagram when used in a religious context because it is claimed that it “introduces an ambiguity in the doctrine and the life of the Christian faith”. 
Its “accuracy” may be attributed to the Forer effect, a tendency for individuals to believe a supposedly tailored description of themselves, yet the description has also been worded in such a general sense as to be interpreted as being tailored specifically for them.
– Source: Enneagram, Psychology Wiki. Last accessed Monday, January 24, 2011 – 12:49 AM CET
Craig Branch writes:
The roots of the enneagram can be traced to two men: George Gurdjieff and Oscar Ichazo. Both men were involved in occultic pursuits.
Guurdjiieff learned of the enneagram from a sect of Sufis (mystical Islam). The Sufis used the enneagram for numerological divination. Oscar Ichazo later developed a personality theory around the enneagram and added it.
Ichazo was deeply involved in psychedelic drugs, shamanism, yoga, even studying mysticism in India and Tibet. Ichazo has received instructions from a higher entity called Metatron and members of his group are guided by an interior master, the Green Qu’Tub.
Another leading figure in the enneagram movement was psychiatrist Claudio Naranjo, associated with the New Age experimental Esalen Institute.
There are many myths associated with the enneagram. One myth has to do with the alleged antiquity of the program when it actually dates in the 1960’s. Another is that it is scientific. Like many New Age practices, its leaders are always trying to assign scientific credentials, but none exists.
And the most important myth is that it can be adapted to fit Christianity. Catholic charismatic lecturer Dorothy Ranaghan has written a well-researched booklet, A Closer Look at the Enneagram, and asks the important question, “If the enneagram is unscientific, esoteric, taken from a contemporary sycretsit version of Islamic mysticism and tainted with the occult, how is it that many Christians have bought into the system so wholeheartedly?” (p. 37)
– Source: Craig Branch, The Enneagram, Watchman Fellowship
 “The Sarmoung Brotherhood was an alleged esoteric Sufi brotherhood based in Asia. The reputed existence of the brotherhood was brought to light in the writings of George Gurdjieff, a [Greeks|Greek]]-Armenian spiritual teacher. Some contemporary Sufi-related sources also claim to have made contact with the group although the earliest and primary source is Gurdjieff himself, leading some scholarship to conclude the group was merely a fictional teaching device” – Source: Samoung Brotherhood, Wikipedia entry. Last accessed Monday, January 24, 2011 – 12:12 AM CET
 Mitch Pacwa, Wikipedia entry.
 See, for instance, Ken Silva, Doug Pagitt Excited About Events Through The Lens Of The Enneagram
 There are also those we do not accept the claims of Sufi origin. See, for instance, Romancing the Enneagram published on a pro-enneagram website.