Redemption is an essential concept in many religions, including Judaism, Christianity, and Islam. The term implies that something has been paid for or bought back, like a slave who has been set free through the payment of a ransom.

In Christian theology, redemption (Ancient Greek: Ἀπολύτρωσις, apolutrosis) refers to the deliverance of Christians from sin and its consequences. Christians believe that all people are born into a state of sin and separation from God, and that redemption is a necessary part of salvation in order to obtain eternal life. Leon Morris says that "Paul uses the concept of redemption primarily to speak of the saving significance of the death of Christ."

In the New Testament, redemption and related words are used to refer both to deliverance from sin and to freeing from captivity. In Christian theology, redemption is a metaphor for what is achieved through the atonement; therefore, there is a metaphorical sense in which the death of Jesus pays the price of a ransom (the Latin word redemptio literally expresses the idea of "buying back" - compare Latin emptus - "having been bought or purchased"), releasing Christians from bondage to sin and death. Most evangelical Protestant theologians and denominations reject Origen's argument that God paid the ransom price of redemption to Satan.

Eastern Orthodox eschatology envisages that the Second Coming will involve universal redemption: "Heaven has become our inheritance. [...] Then we shall have the completion of all things, animate and inanimate, material and spiritual; then shall we have the completion of the work of man's redemption."

The term salvation refers to the overall process of being saved, which includes redemption especially but also encompasses other aspects of the Christian faith such as sanctification and glorification.^{[disputed – discuss]}

A concept similar to redemption in Indian religions is called prāyaścitta, which is not related to the theological sense of sin, but to expiation and personal liberation from guilt or sin. However the end goal of a being is moksha or liberation from karma, resulting in the end of the cycle of birth and death. By attaining moksha, the Atma (self or soul) merges back into Paramatma (God), just as a wave merges back into the ocean.

Like other Indian religions, redemption is more closely related to expiation, but also expects absolution. Pratikramana (lit. '"introspection"'), is a ritual during which Jains repent (prayaschit) for their sins and non-meritorious activities committed knowingly or inadvertently during their daily life through thought, speech or action. Rather than a Prayascitta after perpetrating sin, it is more of a regular conduct, where every possible form of misdeed is recited and repented, if might have been committed, consciously or accidentally. This is also in form of ātma-ālocana ("self-criticism") which is central to Jainism. Vratis and Pratimadharis, including Munis and Aryikas perform Sāmāyika and Pratikramana as a daily essential routine.

In Islam, redemption is achieved by being a Muslim and doing no action that would forfeit one's identification with Islam, being of sincere faith (iman) and doing virtuous actions. Muslim sinners need to turn to a merciful God in repentance and carry out other good deeds, such as prayer (salah) and charity, for redemption. In certain instances, redemption is also linked to seeking forgiveness from the person that has been wronged by Muslims, and obtaining their forgiveness in addition to seeking forgiveness from God directly. As a result of this view of redemption, Muslims have criticized alternative views on redemption, especially the Christian doctrine of original sin.