Theosis

Theosis is the process by which human beings participate in divine life through God’s grace. In Eastern Christian theology, it describes humanity’s transformation into likeness with God without becoming identical to God’s essence.

Grace in Christianity: Grace is God’s freely given favor and action, understood in Christianity as enabling reconciliation and spiritual life. Theosis is understood as transformation made possible by God’s grace.
Essence–energies distinction: The essence–energies distinction separates God’s unknowable essence from the uncreated energies through which God is present and active. It explains how theosis can involve real participation in God without participation in the divine essence.
2 Peter 1:4: Second Peter 1:4 is a New Testament passage that speaks of believers becoming participants in the divine nature. It is the clearest biblical phrase behind the language of participation in divine life.
Justification: Justification is the act by which God declares or makes sinners righteous, understood differently across Christian traditions. Theosis describes salvation as transformation and participation, rather than only a change in standing before God.
Divine simplicity: Divine simplicity is the doctrine that God is not composed of parts or distinct properties. It frames debates over how creatures can participate in God without dividing the divine nature.
Uncreated energies: Uncreated energies are God’s eternal activities and presence, distinguished in Eastern Orthodox theology from God’s essence. Participation in these energies is a central account of theosis.
Irenaeus of Lyons: Irenaeus of Lyons was a second-century Christian bishop and theologian known for opposing Gnosticism and explaining salvation through Christ. His writings connect Christ’s incarnation with humanity’s transformation and life with God.
Sanctification: Sanctification is the process of being made holy through God’s action and human response. It overlaps with theosis but does not always carry the same emphasis on participation in divine life.
Human nature: Human nature is the set of characteristics and capacities understood to belong to human beings. Theosis concerns the fulfillment and transformation of human nature, not its replacement.
Prayer of the heart: The prayer of the heart is a contemplative Christian practice centered on continual inward prayer, often associated with the Jesus Prayer. Hesychast practice presents prayer as a means of communion with God.

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