...God will be 'all in all' (I Cor. 15:28) when we are no longer what we are now, a multiplicity of impulses and emotions, with little or nothing of God in us, but are fully like God , with room for God and God alone. This is the 'maturity' (cf. Col. 1:28) towards which we speed.
Gregory of NazianzusThe Godhead is, to speak concisely, undivided there is one mingling of Light, as it were of three suns joined to each other.
Gregory of NazianzusGod always was, and always is, and always will be. Or rather, God always Is. For Was and Will be are fragments of our time, and of changeable nature, but He is Eternal Being. And this is the Name that He gives to Himself when giving the Oracle to Moses in the Mount. For in Himself He sums up and contains all Being, having neither beginning in the past nor end in the future; like some great Sea of Being, limitless and unbounded, transcending all conception of time and nature, only adumbrated [intimated] by the mind, and that very dimly and scantily.
Gregory of NazianzusHow is it... that the Son and Holy Spirit are not co-unoriginate with the Father, if they are co-eternal with Him? Because they are from Him, though not after Him. 'Being unoriginate' necessarily implies 'being eternal,' but 'being eternal' does not entail 'being unoriginate,' so long as the Father is referred to as origin. So because They have a cause They are not unoriginate... a cause is not necessarily prior to its effects... Because time is not involved, They are to that extent unoriginate... for the sources of time are not subject to time.
Gregory of NazianzusAll who have lived according to God still live unto God, though they have departed this life. For this reason, God is called the God of Abraham, Isaac and Jacob, since He is the God, not of the dead, but of the living
Gregory of NazianzusIf anyone does not believe that Holy Mary is the Mother of God, he is severed from the Godhead. If anyone should assert that He passed through the Virgin as through a channel, and was not at once divinely and humanly formed in her (divinely, because without the intervention of a man; humanly, because in accordance with the laws of gestation), he is in like manner godless.
Gregory of Nazianzus