'God may be' to us 'all in all':

If we too wish to approach God with a pure and spotless affection of heart, we should also retire from all the disturbance and confusion of crowds, so that while still living in the body we may manage in some degree to adapt ourselves to some likeness of that bliss which is promised hereafter to the saints, and that 'God may be' to us 'all in all' (I Cor. 15:23)...When God will be all our love, and every desire and wish and effort, every thought of ours, and all our life and words and breath, and that unity which already exists between the Father and the Son has been shed abroad in our hearts and minds, so that we also may be joined to Him by a lasting and inseprable affection...to possess even in the body an image of future bliss, and that he may begin in this world to have a foretaste of a sort of earnest of that celestial life and glory until the whole life and all the thoughts of the heart become onne continuous prayer.

St. John Cassian, Second Conference of Abbot Issaac