The phrase baptism by fire or baptism of fire, known in English since 1822, is a translation of the French phrase baptême du feu and is a reference to a soldier's first experience under fire in battle. It originates from the ecclesiastical Greek baptisma pyros, in which "fire" is used to mean "the grace of the Holy Spirit as imparted through baptism". Later it was used of martyrdom, especially by fire (e.g. Joan of Arc). Today, it has entered the common vernacular to describe anyone doing something "the hard way" for the first time, particularly if training is necessarily insufficient to fully prepare one for the experience (as is the case with battle).

Mormon Religion

In The Church of Jesus Christ of Latter Day Saints (a.k.a. Mormon Religion) "Baptism by Fire" is in reference to when someone receives the Holy Ghost. This is done after one has already been Baptized by Immersion (a.k.a. by water, or just baptism).

Sources and references

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• EtymologyOnLine
• http://www.biblegateway.com/passage/?search=Luke%203:16;&version=31;