Aside from pentecostal and charismatic Christians, I think that most of us don’t really know what is meant when we hear the Scriptures talking about being “full of the Spirit”, let alone know how to respond to exhortations to “be filled with the Spirit” (e.g. Eph. 5:18). Of course, for charismatic types, the meaning of being “full of the Spirit” is pretty thin as well. Usually it just means manifesting certain supernatural “gifts” of the Spirit.
However, the exhortation to be filled with the Spirit is actually pregnant with some pretty significant theological content. While the role of the Spirit within the Trinity has always been a somewhat sticky point of Trinitarian doctrine, the tradition as a whole is more or less unified in claiming that the Spirit is in some way the agent, the mediator, or the actualization of the eternal relationship of love between the Father and Son. There are, of course many different ways of expressing this basic truth. Augustine spoke of the Spirit as the “bond of love” between the Father and Son. Whereas for Richard of St. Victor, and many of the Eastern Fathers, the idea was more tied to the Spirit as the personal mediator of the relationship between the Father and Son. These differences should not be brushed over, but the point I wish to make here is that there is substantial unity within the tradition that the role of the Spirit in the Trinity must be understood in some sense as the bringing about of the eternal communio of the Father and Son. Whatever else we may say, we must say that the Father and Son love one another in the Spirit.
So, if we understand the person of the Spirit to be constituted by the eternal Trinitarian mission of actualizing and mediating the Father-Son relationship, what might it mean for us to contemplate Scripture’s exhortation to be filled with the Spirit? If we take the immanent Trinitarian mission of the Spirit as constitutive of his economic mission in the theo-drama of salvation (or, more radically, if we identify the two, as I would), then it would seem that to be filled with the Spirit means to be caught up into the relationship of the Son to the Father. Being filled with the Spirit means to be brought into a relationship of sonship with the Father which participates in Christ’s own relationship to the Father. Being filled with the Spirit means, first and foremost to be drawn in a Christoform manner towards the Father. Being Spirit-filled is being embedded in the love of the Father with and in Christ.
Interestingly enough, this means that being full of the Spirit directs us not to the Spirit but to the Father. Be being full of the Spirit we are given, in grace, a share in the Son’s relationship to the Father, we are drawn into the Father’s embrace which unifies all things in koinonial love. So, what could the command to be filled with the Spirit then mean for us? It must mean nothing less than giving ourselves over to the cruciform shape of divine action in our world, accepting Christ’s cross and grave-shaped way of being in obedience to the Father, even to the point of death. Being filled with the Spirit means nothing less than living a life in which the Son’s utter obedience to the Father becomes our own telos and life-form. To be filled with the Spirit is to obey the Father, to be loved by the Father, and to be forever vivified by the Father’s joy in his Son, which raises the dead and calls things into existence which did not exist.