baptism of fire

• baptism by fire

Derived from English translations of the New Testament, namely the Gospels of Matthew (3:11) and of Luke (3:16); from Ancient Greek through Latin; presumably from Aramaic.

baptism of fire (plural baptisms of fire)

1. (Christianity) The gift of the Holy Spirit.
2. (Christianity) Tribulation endured as spiritual discipline.
   • 2013, Conor Moloney as Father Damien, “Mammy?”, in 'Mrs. Brown's Boys', season 3, episode 5:

     And the Father's counselor suggested that he invite you along to help: sort of a re–baptism of fire, so to speak.

3. (Christianity) Martyrdom by immolation.
4. (military, figuratively) The first experience of a severe ordeal, especially a first experience of military combat

   Having to deal with a bomb scare on his first day was a real baptism of fire for John.

• acid test
• throw in at the deep end