Reformed theology, since it is based on a dynamic understanding of the imputation of Christ`s righteousness and on eternal life as its gift, can be called Life theology. Reformed theologians have tried to deploy and deepen the meaning and significances of eternal life by investigating it from their covenantal and salvation-historical perspective. In doing this, they have shown their predominant concern for the merit of Christ imputed to the believers through His continuous mediation. In his commentary on John`s Gospel and Letters Calvin shows his Christological understanding of eternal life. Eternal life refers to the price of Christ`s grace to impute his fulfilled righteousness. It designates Christian life living in communion and communication with Christ who mediates "beyond us(extra nos)" and "within us(in nobis)." Calvin takes special notice of Christ`s working as living light in explaining both the noetic and salvific affection(affectus) of His Spirit, full of grace and truth(Jn. 1:14, 17). Based on this position, Calvin here explores ontological, epistemological, and ethical significances of eternal life. Overall, for Calvin, eternal life embraces becoming true children of God, knowing God and themselves, and living a Christian life according to God`s will. In this way Calvin explores a dynamic concept of Reformed Life Theology.