SOTERIOLOGY. In Christian systematic theology it is used to refer to the study of the biblical doctrine of Salvation. Comes from the Greek terms SOTER meaning Savior or Deliverer and LOGOS meaning “word” “matter” or “thing”
It often includes topics such as the nature and extent of the ATONEMENT as well as the entire process of salvation, conceived as an eternal, divine plan designed to rescue lost and erring sinners and bring them back into ETERNAL fellowship with God. Many regard it as the primary theme in Scripture with the Kingdom of God as its goal. It discusses how Christ’s death secures the salvation and eternal life of those who believe. It also helps to understand the doctrines of redemption, justification, sanctification, propitiation, the new birth and atonement.
Other than Christology, Soteriology is the area where Christianity differs most from cults and other world religions. It help us to know why Salvation is by GRACE ALONE (Ephesians 2.8-9) through FAITH ALONE, IN Jesus Christ alone (Acts 4.12). No other religion bases salvation on faith alone. Philippians 4.7 assures us that our salvation provides a peace that passes understanding because we come to know that He who never fails secures our salvation.
SOTER Strong’s #4990 Deliverer, Savior
SOTERIA Strong’s # 4991 (Used 45 Times in NT)
Romans 1.16, Romans 10.10, Romans 11.11, 13.11,2 Corinthians 6.2, 7.10, Ephesians 1.13
The generic word. It is an all-inclusive word signifying forgiveness, healing, prosperity, deliverance, safety, rescue, liberation and restoration. Christ’s Salvation is total in scope for the total man: Spirit, Soul and Body
SOTERION Strong’s #4992 (Used 5 Times in NT)
Luke 2.30, Luke 3.6, Acts 28.28, Ephesians 6.17, Titus 2.11,
Defender, Defense, Salvation, Rescue, Deliverance, safety, Liberation, release, preservation, and the general word for Christian Salvation.
Acts 28.28 Therefore let it be known to you that the SALVATION of God has been sent to the gentiles and they WILL HEAR IT!
The Protestant Christian perspective on salvation is that no one can merit the grace of God by performing rituals, good works, meditation, self-denial or any other thing because GRACE is the result of God’s initiative without anything from us.
Calvinists believe in the PREDESTINATION of the elect before the foundation of the world. All of the elect persevere in faith because God keeps them from falling away. The Calvinist Doctrine has five points:
ALL have sinned and come short of the Glory of God. People are slaves to sin and self-centered therefore they are unable to Morally choose to follow God.
Unconditional Election is the doctrine which states that God chose those whom he was pleased to bring to knowledge of himself, not based upon any merit shown by the object of his grace and not based upon his looking forward to discover who would “accept” the offer of the gospel. God has elected, based solely upon the counsel of his own will, some for glory and others for damnation (Romans 9:15, 21). He has done this act before the foundations of the world (Ephesians 1:4-8).
This doctrine does not rule out, however, man’s responsibility to believe in the redeeming work of God the Son (John 3:16-18). Scripture presents a tension between God’s sovereignty in salvation, and man’s responsibility to believe which it does not try to resolve. Both are true — to deny man’s responsibility is to affirm an unbiblical hyper-Calvinism; to deny God’s sovereignty is to affirm an unbiblical Arminianism.
Limited Atonement (Particular Redemption)
Limited Atonement is a doctrine offered in answer to the question, “for whose sins did Christ atone?” The Bible teaches that Christ died for those whom God gave him to save (John 17:9). Christ died, indeed, for many people, but not all (Matthew 26:28). Specifically, Christ died for the invisible Church — the sum total of all those who would ever rightly bear the name “Christian” (Ephesians 5:25).
The result of God’s Irresistible Grace is the certain response by the elect to the inward call of the Holy Spirit, when the outward call is given by the evangelist or minister of the Word of God. Christ, himself, teaches that all whom God has elected will come to a knowledge of him (John 6:37). Men come to Christ in salvation when the Father calls them (John 6:44), and the very Spirit of God leads God’s beloved to repentance (Romans 8:14). What a comfort it is to know that the gospel of Christ will penetrate our hard, sinful hearts and wondrously save us through the gracious inward call of the Holy Spirit (I Peter 5:10)
Perseverance of the Saints
Perseverance of the Saints is a doctrine which states that the saints (those whom God has saved) will remain in God’s hand until they are glorified and brought to abide with him in heaven. Romans 8:28-39 makes it clear that when a person truly has been regenerated by God, he will remain in God’s stead. The work of sanctification which God has brought about in his elect will continue until it reaches its fulfillment in eternal life (Phil. 1:6). Christ assures the elect that he will not lose them and that they will be glorified at the “last day” (John 6:39). The Calvinist stands upon the Word of God and trusts in Christ’s promise that he will perfectly fulfill the will of the Father in saving all the elect.
Arminianism agree that all people are born sinful and in need of salvation. Classical Armenians emphasize that God’s free grace enables humans to freely accept or reject the salvation offered through Christ. A person’s saving relationship with Christ is conditional upon faith therefore a Christian can sever their saving relationship with Christ through persistent sin or unbelief. God predestines the elect to a glorious future.
Predestination is NOT the predetermination of WHO will believe but rather the predetermination of the believer’s future inheritance.
Eternal Security is also conditional. ALL believers have full assurance of salvation on the condition that they remain in Christ. Salvation is conditioned on faith, therefore perseverance is also conditioned. APOSTASY or separation from Christ is ONLY committed through a DELIBERATE, willful rejection of Jesus and a renunciation of saving faith. Such apostasy is irremediable and it is what they may call Blasphemy against the Holy Spirit therefore the UNPARDONABLE SIN.
Many in the Pentecostal and Charismatic circles which are for the most part influenced by a theology of works of the Law are negatively opposed to what most Baptist would teach as ONCE SAVED ALWAYS SAVED which in my opinion is the INCORRECT terminology because it’s focus is on works such as tithing, church attendance, reading of the Bible, behavior, conduct etc. I believe a much better way to understand salvation is to understand that ONCE A SON ALWAYS A SON. It is based on unconditional love and INFINITE GRACE.
Protestant beliefs about salvation. This table summarizes the classical views of three Protestant beliefs about salvation.
Human will Total depravity:  Humanity possesses “free will”,  but it is in bondage to sin,  until it is “transformed”.
Total depravity:  Humanity possesses free will in regard to “goods and possessions”, but is sinful by nature and unable to contribute to its own salvation. 
Humanity possesses freedom from necessity, but not “freedom from sin” unless enabled by “prevenient grace”.
Election Unconditional election.
Conditional election in view of foreseen faith or unbelief.
Justification and atonement Justification by faith alone. Various views regarding the extent of the atonement.
Justification for all men,  completed at Christ’s death and effective through faith alone.
Justification made possible for all through Christ’s death, but only completed upon choosing faith in Jesus.
Conversion Monergistic,  through the means of grace, irresistible.
Monergistic, through the means of grace, resistible.
Synergistic, resistible due to the common grace of free will.
Perseverance and apostasy Perseverance of the saints: the eternally elect in Christ will certainly persevere in faith.
Falling away is possible,  but God gives gospel assurance.
Preservation is conditional upon continued faith in Christ; with the possibility of a final apostasy.
Union with Christ
The expression “in Christ” (and its derivatives) is used in the NT to express our union with Christ as believers. It encompasses the whole spectrum of our salvation from its conception in the mind of God to its consummation in the new heavens and the new earth. Our election was “in Christ” (Eph 1:4) and so are all the ensuing benefits, namely, our calling, redemption regeneration, conversion, justification, adoption, sanctification, and glorification (Rom 8:29-30, 38-39; 1 Cor 1:30; John 15:1-11; 1 John 2:5-6). Our entire present experience and future destiny is “in Christ.”
Our experience of death to sin and resurrection to new life is in light of our union with Christ in his death and resurrection. Thus, not only are we “in Christ” but he (as well as the Father and the Spirit) is also in us (John 14:23) and through His indwelling Spirit we are sanctified in Christ and increasingly conformed/transformed to his image (Rom 8:29; 2 Cor 3:18). And, all believers are “one body” in Christ Jesus which itself is a spiritual reality that should give rise to zealous efforts to develop unity (not disunity or uniformity) among true believers (Rom 12:5; 1 Cor 10:17; Eph 4:4).
Just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, 5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, 6 to the praise of the glory of His grace, by which He made us accepted in the Beloved. In Him we have redemption through His blood, the forgiveness of sins, according to the riches of His grace. Ephesians 1.4-7 NKJV
Adoption is a wrong translation of the word HUIOSTHESIA (Huios= Sons, Thesia= made or incorporated) it refers to God’s decision to make us members of his family and to offer us all the benefits and (ethical) standards involved in living “under his roof.” If justification deals with my legal standing before God as a sinner, then accepted deals with my familial relationship to the Father; I am now one of his own children through the new birth of incorruptible seed (1Peter 1.23) and he has become my Father. In many different texts—many more than one finds in the Old Testament—the New Testament claims that God is our special Father through the gospel and that we are his children. It is in the context of this new relationship that we receive many, great blessings.
Paul describes to Titus the SUMMARY of SALVATION:
But when the kindness and the love of God our Savior toward man appeared, 5 not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit, 6 whom He poured out on us abundantly through Jesus Christ our Savior, 7 that having been justified by His grace we should become heirs according to the hope of eternal life. 8 This is a faithful saying, and these things I want you to affirm constantly, that those who have believed in God should be careful to maintain good works. These things are good and profitable to men. Titus 3.4-8