Even the gifts that the Spirit dispenses to individuals are given by the Father through the Word. For all that belongs to the Father belongs also to the Son, and so the graces given by the Son in the Spirit are true gifts of the Father. Similarly, when the Spirit dwells in us, the Word who bestows the Spirit is in us too, and the Father is present in the Word. This is the meaning of the text: My Father and I will come to him and make our home with him. For where the light is, there also is the radiance; and where the radiance is, there too are its power and its resplendent grace.
From a letter by St Athanasius
I found this fascinating, taken from the Office of Readings for Trinity Sunday, because it continues to disappoint me that anyone would make a schismatic point about the procession of the Holy Spirit from the Son. We have that in the Latin Rite creed and the Orthodox object to it. Well here is St. Athanasius, an eastern Father, I believe, and he is very clear about what it means. As a Greek Orthodox friend once told me, the division really is more about the bishop of Rome. In the meantime, the schism and various Protestantisms continue to weaken the sign to the nations. Seems to be mirrored in the all too common splintering of marriages and families.