If you walk up to a random person on the street and tell them that they need to be saved, they will probably think to themselves that they really don't need to be saved from anything, because they see no danger. What do humans really need to be "saved" from, in a spiritual sense? I would say that people need to be saved from:
- The preeminence of sin over their life
- The power of sin in their life
- The presence of sin
- The penalty of sin
"For by grace you have been saved through faith, and that not of yourselves; it is the gift of God"
1 Corinthians 1:18
"For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God."
"Much more then, having now been justified by His blood, we shall be saved from wrath through Him."
As you can see, salvation is not only in the past, but also the present and future. I would encourage you also to read this website, LinkToAwesomeWebsite , which has another few awesome verses about this past/present/future deal. Anyway, if we have not yet attained our future salvation, how can we "lose" it? You cannot lose something you do not have. All we actually have right now is the salvation from the preeminence of sin in our lives, and the promise of ongoing and future salvation. That promise is God's promise, and God's promises always come to pass. If God promises that you will be saved in the end, then no matter what you or anyone else tries to do to stop that plan, you WILL be saved. It's that simple.
"And I give them eternal life, and they shall never perish"
Never here is translated as "never." If Christ gives someone eternal life, they will never perish. Ever. Not now, and not in the future. That is a promise.
To go along with this whole idea that we have the promise of future salvation, there is the doctrine of predestination. That's a long word. Predestination means that before the world was ever formed, God choose our destinies. Before we ever existed, God mapped out our eternal destiny. Take for example a christian: God knows from eternity past that this person will accept Christ as Savior and pre-destines that person to be saved from sin, and from the eternal penalty of sin.
"For whom He foreknew, He also predestined to be conformed to the image of His Son..."
"Moreover whom He predestined... these He also glorified."
We'll call this guy JoeTheWishyWashyChristian. So, from eternity past, God has chosen that JoeTheWishyWashyChristian will be with Him in heaven forever. Then, at about 0 AD, or 33 AD, or whenever, Christ personally pays for all the future sins of JoeTheWishyWashyChristian. Now time rolls on, and in 1984, JoeTWWC (his nickname now) accepts Christ as His Savior and is Born again. So far, so good. Now, during 1984, JoeTWWC is "saved" and so we know that his future is (as predestined from eternity past) heaven. Time rolls on again, and in 1994, JoeTWWC turns away from God and states that he doesn't want Christ to be His Savior. When he dies, then, God sends him to hell. Wait - what? We already established the facts that:
- God predestined JoeTWWC to be conformed to the image of His Son and to go to heaven
- Everything God promises or predestined will come to pass
- Therefore, it does not logically follow that JoeTWWC could possibly end up in hell
Philippians 1:6...will continue conforming him into the image of Christ, and will eventually welcome him into heaven.
"being confident of this very thing, that He who has begun a good work in you will complete it until the day of Jesus Christ"
Think of all the fictitious stories of people who sold their soul to the devil... the whole concept of selling their soul was that they couldn't just undo the deal later. They were afraid that they couldn't get it back. In a much less scary way, if you give yourself to God, and you belong to Him, you can't just undo the deal later. God is more powerful than the devil, you know. ;)
So basically, being rescued in not generally something that can be undone. The whole idea of undoing a salvation situation doesn't really make sense. Secondly, what we have in regard to salvation from eternal damnation is futuristic: we only have a promise. That's important because we know that whatever God promises will come to pass. Finally, a christian has been predestined, and that's in the past - there is no way to lose that, or otherwise get around it.