In Eastern philosophies, as well as the pre-Socratics, essentially took the position that either being or becoming was an illusion. For the Vedanta school of Hinduism, Atman (the self) is Brahman (being/God). Consequently, becoming is unreal and an illusion (Maya), and only being is real. Within the Hellenic world, Parmenides essentially took the same position. In Buddhism, and the Greek Milesians speculators, the opposite was the case: There was no stable ground of being, only becoming. For Buddhists, the whole empirical world is nothing but an illusion of stability. Everything is empty, everything is a grey "suchness." For the Milesians, as well as for the later Epicureans and Atomists, everything was the flux of a certain "Ur-stuff" of reality- water, earth, atoms, etc.
The difficulty with either of these approach is obvious. First, they have a tendency of accounting only for some datum of reality (namely either the phenomenon of being or becoming) and not the other. They simply dismiss being or becoming as illusion when it does not fit into their comprehensive description of reality. Secondly, either solution logically collapses into a form of nihilism. If all temporality is illusion, and there is nothing but undifferentiated being, then nothing I do in my temporal life is meaningful- since flux and the becoming (within which the moral life is lived) is illusory. Conversely, if I posit that all is mere temporality, then there is nothing but the flux of my becoming. Therefore my existence lacks an eternal and stable meaning. Stability of truth and meaning can only be an actuality with reference to an eternal and unchanging reality.
Plato and Aristotle were in many ways able to improve on this. For Plato, being and becoming are both realities. The "Good" and the realm of the forms, exists as a stable ground of all reality. Temporal reality echoes the eternal realm. Becoming gains meaning by imaging being. In the case of Aristotle, the form/matter distinction help relate being and becoming to one another in temporal objects. The form exists as the stable reality at core of individually subsisting things. It represents the unchanging inner reality which actuates itself through the becoming of change and growth of the individually subsisting thing. Matter of course accounts for the individuation and change in the object, which form (the organizing principle) utilizes.
Nevertheless, the difficulty with both these approaches is that they still operated within the assumption that being is more real than becoming. Moreover, they relate being and becoming to one another in the most tenuous of fashions. For Plato, temporality was an unreal shadow of being. The individual soul's goal was to escape the unreality of becoming for the reality of being. Beyond this, he posits that the realms of being and becoming were both eternal and utterly separate. The only thing which related them was the existence of the Demiurge who fashioned eternal matter into objects resembling the eternal forms. In Aristotle, God who is "pure act" and the "prime mover," simply moves eternal matter in an eternal process. Becoming is therefore subsumed into an eternal process of "pure actuality" (God) actualizing temporal potency into act. In this sense, becoming is less real than being in that it is an eternal and unending effect of being.
The Christian account of the Trinity is able to overcome this aporia between being and becoming. In that God is eternal and immutable, he is the stable ground of all reality. Nevertheless, he also contains the reality of becoming within himself. The Father is ever begetting the Son, and the Father and the Son are ever breathing forth the Spirit. Neither does the fact that God exists through his act of becoming mean that the divine being collapses into becoming (the fallacy of Hegel, German Idealism, Jungel, Moltmann, etc.). Rather, in becoming, God eternally corresponds to himself without growth or flux. The Son and the Spirit are the perfect images of the Father, the font of divinity. Paradoxically, God eternally corresponds to himself in his act of becoming.
In that God is an eternal being subsisting in the event of becoming, he is both capable of providing a stable meaning and goal of temporality, while at the same time containing within himself the already existing exemplary reality of becoming. As the exemplary reality of becoming, he can communicate both being and becoming to his creature through his act of creation ex nihilo. Becoming is not merely a derivative effect of being, or perhaps the manifestation of the instability and unreality of all that is not being. Rather, possessing an exemplary reality in God himself, it is just as real and meaningful as being.
For this reason, the meaning of temporality is always ecstatic, and never self-contained- just as God himself subsists through ecstatic relationships of Father, Son, and Holy Spirit. The meaning of temporality subsists in its relationship to its source in the eternal Word of God. The eternal Word of God is both the source and transcendent horizon within which temporal reality is lived out. The Incarnation is the fulfillment of this truth. The eternal and universal God subsumes into his being temporality (i.e., Christ's human nature) and therefore bestows on a series of temporal event (the life of Christ) universal significance. Christ (we are told by the NT documents), represents the future of creation. In this, the eschatological horizon of being is therefore opened up for temporal creatures, in that their lives possess an eternal meaning insofar as they are subsumed into the historical reality of the person of Christ: "Your life is hidden in God in Christ."