Deliverance by a ‘redeemer’ from some evil by paying a price. Slaves could be redeemed (released) by that means. If an ox gored someone to death, the irresponsible owner was liable to execution, but a ransom could be paid to rescue him (Exod. 21: 30). The kinsman who has the right to redeem by payment is known as the go'el in Hebrew, and the same word is used of Yahweh as the deliverer of his people (Isa. 41: 14). The epistles claim that Christ redeemed people ‘from the present evil age’ (Gal. 1: 4) or bondage to the devil (Heb. 2: 14–15). This redemption is both already effected (Rom. 8: 29) and yet also awaiting final completion with the destruction of death (Rom. 8: 23). As in the OT, NT writers also mention that God has redeemed a people for himself (Rev. 5: 9), and the death of Christ is proclaimed as redeeming mankind from the consequences or punishment for their sins (Gal. 3: 13).
There was a doctrine of a Redeemer in Gnosticism. He was thought to descend in disguise to the earth from a spiritual realm to enlighten mankind with some knowledge (gnosis) of their identity. Gnosticism in a Christian setting did not regard the work of Christ as delivering from sin but rather as leading people to self-realization.