Based on Bultmann's theological thinking and his existentialist hermeneutics, the article focuses on justification and its relation with faith as an eschatological event as obedience and decision founded on the act of the God's grace according to the theology of the Apostle Paul. Thus, the article points out that, consisting of the God's justice in a possibility for the listeners of the preaching before the absolute character of the dominion exercised by the power of sin in a process that subjugates all human beings to slavery and implies the impossibility of justification before of God through the works of the Law, faith as obedience and decision constitutes the eschatological event in a construction that encloses it as the new salvific path that, emerging as the law of faith, opposes the law of works, converging to justification as God's justice. Thus, if faith is a concession from God in a movement that contains the idea of predestination, such characterization does not imply, however, an operation that exempts the human being from the responsibility of the decision-making act but consists in the fact that the referred possibility it maintains absolute dependence on the God's grace and, thus, constitutes an event in which the decision can only emerge as a gift from God.