What is Matthean fulfillment (plerosis)? According to a triplex via of fundamental continuity, radical discontinuity, and transcendence-completion, it is the process of Christification by which those in communion with Christ become agents of his theandric activity. In light of this paradigm, the divine 'with-ness' which Christ brings his people is more profoundly appreciated. The fullness which God's covenant people enjoy via communion with Christ is nothing less than the very fullness of God: they participate in his life and love, power and providence, righteousness and perfection, virtue and glory, identity and mission. In this monograph, Andrew D. Dalton argues that plerosis is an ongoing and ever deepening process of deification: in and through the King of kings, God has filled inaugurally, is filling perpetually, and will fill consummately his church-kingdom Israel with his own divine fullness.