Salvation
Main article: Salvation
Christians believe
salvation is a gift by
unmerited grace of God, who sent Jesus as the savior. Christians believe that through faith in Jesus one can be saved from
sin and spiritual
death. The crucifixion of Jesus is explained as an
atoning sacrifice, which, in the words of the
Gospel of John, "takes away the sins of the world". Reception of salvation is related to
justification.
[24]
The operation and effects of grace are understood differently by different traditions. Catholicism and Eastern Orthodoxy teach the necessity of the free will[25] Reformed theology places distinctive emphasis on grace by teaching that mankind is completely incapable of self-redemption, but the grace of God overcomes even the unwilling heart.[26] to cooperate with grace.
The Trinity
Main article: Trinity

The
Hospitality of Abraham by Andrei Rublev: The three angels represent the three persons of God
Most Christians believe that God is spirit (
John 4:24), an uncreated,
omnipotent and eternal being, the creator and sustainer of all things, who works the redemption of the world through his Son, Jesus Christ.
Against this background, belief in the
divinity of Christ and the Holy Spirit was expressed as the doctrine of the
Holy Trinity,
[27], which describes the
single Divine substance existing as three distinct and inseparable persons: the Father, the Son (Jesus Christ the eternal Word), and the Holy Spirit. According to the doctrine, God is not divided in the sense that each person has a third of the whole; rather, each person is considered to be fully God (see Perichoresis). The distinction lies in their relations, the Father being unbegotten, the Son begotten of the Father, and the Holy Spirit proceeding.[28] "Begotten", in these formulae, does not refer to Mary's conceiving Jesus, but to the Son's relationship to the Father, which is described as being "eternally begotten" of the Father.
Trinitarian Christian also conceive of salvation as one work of the triune God, in which "the three divine persons act together as one, and manifest their own proper characteristics."
[29]
Trinitarian Christians trace the orthodox formula of the Trinity — Father, Son, and Holy Spirit — back to the resurrected Jesus himself, who used this phrase in the
Great Commission (
Matthew 28:16-20).
Most Christians believe the Holy Spirit inspired the Scriptures,
[30] and that his active participation in a believer's life (even to the extent of "indwelling" within the believer), joining the believer's free actions with his own, is essential to living a Christian life.
[31] In Catholic, Orthodox, and some Anglican theology, this indwelling is received through the sacrament called
Confirmation or, in the East,
Chrismation. Most Protestant traditions teach that the gift of the Holy Spirit is symbolized by baptism; however some (Baptists and comparable groups) do not attribute any sacramental significance to baptism. Pentecostal and Charismatic Protestants believe the
baptism with the Holy Spirit is a distinct experience separate from other experiences like conversion or water baptism, and many Pentecostals believe it will always—or at least usually—be evident through
glossolalia (speaking in tongues).
Non-Trinitarians
Main article: Nontrinitarianism
In antiquity, and again following the Reformation, several sects advocated views contrary to the Trinity. These views were rejected by many bishops such as
Irenaeus and subsequently by the
Ecumenical Councils. During the Reformation, though most Catholics, Orthodox, and Protestants accepted the value of many of the Councils, some groups rejected these councils as spiritually tainted.
[32] Clement Ziegler,
Casper Schwenckfeld, and
Melchior Hoffman advanced the view that Christ was only divine and not human.
Michael Servetus denied the divinity of Christ, as did others who were tried at Augsburg in 1527.
[33]
Modalists, such as
Oneness Pentecostals, regard God as a single person, with the Father, Son, and Holy Spirit considered modes or roles by which the unipersonal God expresses himself.
[34]
Latter-day Saints accept the divinity of the Father, Son, and Holy Spirit, but deny that they are the same being, believing them to be separate beings united only in will and purpose.
[35] (see
Godhead)
Present day groups who do not consider Jesus to be God include
Unitarians,
[36] descendants of Reformation era
Socinians and
Jehovah's Witnesses.
[37]