Salvation
Not one of us has led a perfect life; everyone has sinned. God cannot accept sin to the point that it is destroyed if it comes into his presence. Therefore because of this sin we are separated from God.
The word salvation means “to be preserved or delivered from ruin, harm, or loss” . In the Christian sense the ruin, harm or loss is the eternal punishment that comes with the separation from God that results from our sins. In short, salvation is deliverance from the wrath (anger) of God. Instead of that punishment, those who have salvation will enjoy eternal life.
Whoever is trusting in the son, has the eternal life, and whoever disobeys the son shall not see the life, but the anger of God shall abide upon him. (John 3:36)
Salvation is and always has been a gift from God, an undeserved expression of grace by God toward mankind. There is nothing that we can do or give to obtain salvation.
This gift is available and offered to everyone but it must be received, accepted. It can only be received by faith in God. Even this faith in God, however, is a gift from God. No part of our salvation results from who we are or what we have done.
For it is by his grace that we have been saved through faith, and this faith was not from you, but it is the gift of God, 9 not of works, lest anyone should boast. (Ephesians 2:8-9)
Although the gift of salvation is offered to all, most people reject it because they reject God.
Salvation has always been by faith. It was that way in the Old Covenant and it was that way before the Old Covenant. There was never a time when salvation could be earned by works, by doing good things.
For what do the Scriptures say? "Abraham believed God, and it was accounted to him for righteousness.” (Romans 4:3)
Just as Abraham believed God and it was accounted to him for righteousness (Galatians 3:6)
By faith, Abel offered to God a sacrifice much better than that of Cain, and because of it there is a testimony concerning him that he was righteous. 6 But without faith, no one can please God, for whoever is brought near to God must believe that he exists and that he is the rewarder of those who seek him. 7 By faith, Noah worshiped, […] and he became the heir of the righteousness which is in faith. (Hebrews 11:4,6-7)
Hebrews 11, in total, makes it clear that salvation has always been by faith, before the Old Covenant and during it. Jesus’ redemptive sacrifice covers all who had faith in God, those who lived prior to his sacrifice and those who lived during and after.