No, the Rastafarian god 'Jah,' is not the same as the biblical God. Developed in the 1930s, Rastafari, or Rasta, combines parts of biblical truth and Jewish religion with the teachings of Marcus Garvey who believed that Haile Selassie I, emperor of Ethiopia from 1930–1975, was the second advent of Christ.
Is the Rastafarian / Rasta god Jah the biblical God?
The Rasta's Jah is not triune (Father, Son, and Holy Spirit), therefore it is not the same as the one true God of the Bible. Selassie did not fulfill scores of prophesies about Jesus' return and is a false messiah.
The name Jah comes from the King James Version of Psalm 68:4 which calls God by the name JAH, the shortened version of YHWH, or Yahweh (Jehovah). So Jah is a biblical name for God, but merely using this name doesn't bestow users with a knowledge of, nor a relationship with, Jesus. Rastas do not worship the God of the Bible.
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Truth about Religion