Fili-what?!

The "filioque" or "...and the Son" as it is called in English was inserted into the Nicene Creed by the Spanish and then Franco-Catholic church and eventually, by around 1054ad was accepted wholly by the Roman Papacy at which time the Pope of Rome anathematized the Eastern Patriarch hate of Constantinople for not accepting it.

Why did the Orthodox Patriarchs of the East care so much as to whether the Holy Spirit proceeds from the Father, or from the Father and the Son?
A better question, is what does it mean for the Spirit to proceed?

To proceed forth from means to have an origen, a place from whence things begin. We know from scripture and tradition that all things have their beginning in the Father. We know also that Christ, the lover of mankind, is the Divine Incarnation of the Word, Logos, and came to save mankind from his fall. But of the Holy Spirit what do we know?

The Holy Spirit is the third person of the Trinity, one in essence with the Father and the Son. Just like the Son, there is no time at which the Spirit did not exist. Together, they are "Elohim" or God with us. The Holy Spirit is the visitor who comes in many forms throughout the time of Israel's prophets, and yet in describing exactly who He is, demands a certain anonymity.

Vladimir Lossky writes:

"Here it may be stated that the relations only serve to express the hypostatic diversity of the Three; they are not the basis of it. It is the absolute diversity of the three hypostases which determines their differing relations to one another, not vice versa. Here thought stands still, confronted by the impossibility of defining a personal existence in its absolute difference from any other, and must adopt a negative approach to proclaim that the Father– He who is without beginning (anarchos)– is not the Son or the Holy Spirit, that the begotten Son is neither the Holy Spirit nor the Father, that the Holy Spirit, "who proceeds from the Father," is neither the Father nor the Son.{14} Here we cannot speak of relations of opposition but only of relations of diversity.{15} To follow here the positive approach, and to envisage the relations of origin otherwise than as signs of the inexpressible diversity of the persons, is to suppress the absolute quality of this personal diversity, i.e. to relativize the Trinity and in some sense to depersonalize it."

In other words, to go beyond this, using an affirmation about how the Holy Spirit relates to the Son, actually implies a rationalistic interpretation which is devoid of mystery and goes completely against the scriptures.

Furthermore, in explaining the relationship any more than has originally been explained through the scriptures and the creed, one risks reducing the personhood of the Holy Spirit to something less of a person and more of a power or energy of the first two persons of the Trinity, and inevitably deconstructs the mystery of the Triune Godhead. We can see the end result of this in the modern Protestant evangelical church which teaches that the charismatic shaking, unintelligible language and convulsions, handling snakes and all other sort of behavior is their proof that they are imbued with the "Spirit". For Orthodox Christianity, there is no time when the Father, Son and Holy Spirit are separate, and all are equal yet unique in personhood. The church has always upheld this, from the very beginning. Just as Christ is of one essence with the Father, so is the Holy Spirit. This is the Mystery of the Triune Godhead.