The pure meaning of the word Salvation according to the Bible is rescue, deliverance, remedy, especially from sin.
1. The root Hebrew word is yasha’—“to be wide or roomy” in contrast to “narrow, restricted, or confined.” It refers to delivering a person or group of people from distress or danger, from their “restricted” predicament in which they are helpless to deliver themselves. It carries the idea of liberation, protection, emancipation, and preservation. Sometimes the deliverer was human (Judges 2:18); sometimes the Deliverer was YHWH (Psalm 20:6; Isaiah 61:10). Sometimes an individual was delivered (Psalm 86:1-2), sometimes the nation Israel (Isaiah 12:2), sometimes the entire world (Isaiah 45:22; 49:6). Faith was the necessary condition for salvation that led to personal righteousness (Genesis 15:6) and the object of faith was the true God (Numbers 14:11; Psalm 78:22; Jonah 3:5). The initiative was always entirely with God (Psalm 3:8; Jonah 3:5).
2. Both the Septuagint (Greek translation of the Old Testament) and the New Testament use the Greek word sozo (soter, soteria) to translate yasha’ and sometimes shalom (peace or wholeness). The New Testament usage can be expanded to include cure, recovery, remedy, rescue, redemption, or welfare. This deliverance can be from danger, disease, or death (Matthew 9:22; Acts 27:20; Hebrews 5:7). The full-orbed Christian usage means delivering from eternal death and gifting a person with everlasting life (Romans 5:9; Hebrews 7:25). As in the Old Testament, the initiative of salvation is entirely with God (John 3:16). But the New Testament makes sure that we understand that all salvation is based solely on the Lord Jesus Christ’s death on the Cross (Acts 4:12; Hebrews 5:9).
3. The simple usage of these biblical terms only introduces the wonder of our so great salvation we must not neglect (Hebrews 2:3). Other, more theological terms (see below) like sacrifice, propitiation, reconciliation, redemption, and justification must be considered to accurately appreciate and understand the doctrine of soteriology.
The doctrine of salvation...embraces all of time as well as eternity past and future. It relates in one way or another to all of mankind, without exception. It even has ramifications in the sphere of the angels. It is the theme of both the Old and the New Testaments. It is personal, national, and cosmic. And it centers on the greatest Person, our Lord Jesus Christ." (Charles Ryrie, Basic Theology, p 319)