Salvation is the spiritual phenomenon concerned with the rescue of sinners from eternal damnation. The Bible declared that the wage of sin is death (Romans 6:23). Thus, every sinner has already been condemned to spiritual death as a result of our sinful nature inherited from our first parents, Adam and Eve. We need Salvation because we cannot save ourselves, being that a condemned criminal cannot save himself. Jesus came to make propitiation for our sins, and He paid the full price as a result of His Crucifixion and Death on the Cross. Because man cannot save himself and Angels cannot pay for the sins of the human race, God has to give part of Himself in the Person of His only begotten Son that became man in order to save men. Thus, Jesus became the Son of Man as well as the begotten Son of God.
We need Salvation because the Bible declared that we have all sinned and come short of the glory of God (Romans 3:23). To regain the relationship between man and God that was seriously damaged due to the sins of our first parents, Jesus came to reconcile us to God.
We need Salvation so that we can transform from our evil ways to become men and women of goodwill. Because we are naturally people that are enslaved to sin as a result of our perverted nature, we need the deliverance that comes to us through the Salvation of our souls.
Because of the war that is constantly waging in our conscience (Romans 7:15), we need Salvation so that we can desist from our evil ways. Because of our depraved nature, we need the empowerment of the Holy Spirit so that we can begin to live the way God expects us to live.
We also need Salvation so that our sins can be forgiven and we can be free from the consequence of our evil deeds (Acts 2:38). Of course, because there is life after death, Salvation is necessary so that we can live in the presence of God in eternity. Because there is a penalty that awaits every unrepentant sinner, we need the precious blood of Jesus to cleanse us from all unrighteousness so that we will not spend eternity in hell.