Universalism is a major spiritual tradition dating back to the Apostles of Jesus Christ and the ancient Christian church. It is an understanding of the Gospel that has inspired saints, mystics, philosophers, theologians, and churches in nearly every era of religious history from the time of Jesus to today. Even before the proclamation of the Christian Gospel, there were foreshadowings of Universalism in the Hebrew scriptures as well as in Greek and Eastern philosophy — some of which taught the truths of reformative divine justice, the potential of all people to be perfected in the divine image, and the emanation and restoration of all things back to the Source of All Being.
Numerous verses in the writings of
St. Paul speak of God’s plan for the ultimate reconciliation of all, and Paul approvingly referred to the practice of baptism on behalf of the dead in the Corinthian church he founded (1 Cor. 15:29). This practice presupposes that God will save even those who died in sin and unbelief. Paul’s vigorous and courageous efforts to spread the Gospel of Jesus Christ were probably the most important factor in the development of Christianity as a major world religion. He was at the forefront of the movement to include non-Jews in God’s new community of faith and to broaden the understanding of salvation beyond the confines of Jewish law. Paul created an intellectually coherent view of the meaning and message of Christ that was heavily focused around the teaching that through successive ages of time,
God is in the process of bringing all beings back to Himself — that through the transformative influence of His firstborn Son, the Christ, all people can be raised up into the station of mature sons and daughters of God (e.g. see 1 Cor. 15:22-28, 2 Cor. 3:18, Gal. 4:4-5, Eph. 5:1).
The early church from the time of the Apostles until the 4th century was primarily a Universalist church. Most of the church fathers during this period believed that all people will be saved. Over time, alternative doctrines about the fate of sinners grew more popular, such as annihilationism and eternal conscious torment. These doctrines were often held by Christians who could not read the New Testament in the original Greek language in which it was written, and who interpreted the Bible through the lens of barbaric forms of paganism. It is noteworthy that Irenaeus the Bishop of Lyons wrote a lengthy book called
Against Heresies in the late 2nd century, which never once mentioned universal salvation as a heretical belief. This is because for the first few centuries of Christian history,
Universalism prevailed as the mainstream understanding of the Gospel.~The History of Universalism – The Christian Universalist Association