The purpose of this article is to investigate the idea of apokatastasis panton (universal Salvation) of the radical pietists, J. W. and J. E. Petersens. The idea of apokatastasis panton had existed before the traditional view of twofold eternal destiny(blessedness and damnation) was established. The idea of apokatastasis panton was systematized by Greek Father Origenes who was condemned as heretical at the Fifth Ecumenical Council in Constaninople in 553. The Reformers such as Martin Luther and John Calvin also condemned the idea of apokatastasis panton as heretical. Despite its problematic nature, the idea has intermittently attracted speculative minds. During the Reformation, certain spiritualist and Anabaptist group advocated the idea of apokatastasis panton. Therefore the Confessio Augustana and the Reformed Confessio Helvetica Posterior also condemned the idea. In more recent times it was especially Radical Pietism that strongly propagated the idea that was abandoned. J. W. and J. E. Petersens as Radical Pietists were the unique and fascinating figures who reignited the pilot light of the idea of apokatastasis panton in the Protestant world. They were in the initial stages influenced by the Pietist Father Ph. J. Spener’s eschatological view represented through “Hoffnung besserer Zeiten für die Kirche auf Erde.” They went further and without hesitation accepted and enthusiastically widespread the idea of apokatastasis panton. They argued that the idea of twofold eternal destiny after the last judgment contradicts the loving God who created the world as something very good and has through Christ redeemed the whole creation without any exception. They believed that evil cannot prevail against God’s original blessing and that “where sin increased, God’s grace increased much more”(Rom 5:20). They tried to ground their arguments upon the Bible. They agreed that the last judgment will take place and the unrighteous who don’t accept the gospel to the end and reject it, are destined to eternal punishment. However, they understand “eternal” in the sense of limited span compared to that of God. J. W. and J. E. Petersens did not agree that the teaching of apokatastasis panton would destroy not only the seriousness of sin, but also the urgency of repentance. Rather, they thought that the teaching of apokatastasis panton makes all humans realize the universal love of God and move them to live a grateful better life.