In accordance to orthodox Christian teaching, salvation refers to the gracious act of God’s grace in delivering his people from bondage to sin and condemnation, transferring them to the kingdom of His beloved Son (Col. 1:13), and giving them eternal life (Romans 6:23)—all on the basis of what Christ accomplished in his atoning sacrifice, burial, and resurrection (Eph. 2:8-10). In theology, the study of salvation is dubbed soteriology, from the Greek soteria (Σωτηρία) meaning “salvation”. My Reformation Study Bible, ed. by R.C. Sproul, Sr., (Nashville, TN: Thomas Nelson, 1995) articulates the basics of the Christian “Salvation” (p. 1718). Therein it notes:
The central theme of the Christian gospel is salvation. The gospel proclaims that as God saved Israel from Egypt and the psalmist from death (Ex. 15:2; Ps. 116:6), so He will save all who trust Christ from sin and its consequences. The salvation from sin and death is wholly God’s work. “For by grace you have been saved through faith, and not of yourselves; it is the gift of God” (Eph. 2:8). “Salvation is of the Lord” (Jon. 2:9).
The Hebrew words that express the idea of salvation in the Old Testament have the general sense of deliverance from physical danger or moral distress (Ps. 85:8-9; Is. 62:11). In such passages, the Septuagint (the Greek translation of the Old Testament) uses Greek words that mean to save from death or dangers, as well as to preserve or to heal. New Testament passages that speak of salvation use all these ideas to explain the acts of God on behalf of the lost.
Salvation delivers the believer from the wrath of God, the dominion of sin, and the power of death (Rom. 1:18; 3:9; 5:21; 1 Thess. 5:9). God liberates sinners from the natural condition of being mastered by the world, the flesh, and the devil (John 8:23-24; Rom. 8:7-8; 1 John 5:19). He frees believers from the fears that a sinful life guarantees (Rom. 8:15; 2 Tim. 1:7; Heb. 2:14-15), and from the vicious habits that enslaved them (Eph. 4:17-24; 1 Thess. 4:3-8; Titus 2:11-3:6). Salvation brings not only the promise of spiritual wholeness and peace, but also of physical healing (Matt. 9:21-22; Mark 10:52 and text note; James 5:15). Although Christians have already received salvation, they will experience the benefits of salvation in their fulness only when Christ returns at the end of the age (Heb. 9:28; 1 Pet. 3-5).
Salvation is accomplished through what Christ did in history and by what He continues to do in believers by the Holy Spirit. The basis for our salvation is Jesus’ death on the cross (see “The Atonement” at Rom. 3:25) and the righteousness. He achieved for us in His active obedience. It is realized in our lives in His active obedience. In is realized in our lives as Christ lives in us (John 15:4, 17:26; Col. 1:27) and we live in Christ, united with Him in His death and risen life (Rom. 6:3-10; Col. 2:12, 20; 3:1). This vital union, sustained by the Spirit through faith and formed in our new birth, presupposes our eternal election in Christ (Eph. 1:4-6). Jesus was foreordained to represent us and to bear our sins as our substitute (1 Pet. 1:18-20; cf. Matt. 1:21). We were chosen to be effectually called, conformed to His image, and glorified by the Spirit’s power (Rom. 8:11, 29, 30).