Throughout the Bible we see that the process of salvation is likened to irreversible processes. We are sealed with the Holy Spirit until death. A seal set by God, a seal that IS God, cannot be broken. We are regenerated, and as far as I know, a person cannot be "unregenerated." Our sins are as far away from us as the east is from the west, and so far, the west has never caught up with the east. As far as God is concerned, our future life is so set in stone that He says we've already passed from death into life, and will never come into judgment.
John 5:24 “Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life.”
Irreversible. Remember that word. You cannot be un-born...
As well as our salvation being irreversible, we cannot separate ourselves from God. We are close to God, as christians, having God as a Father, being "in Christ," and being "indwelt by the Holy Spirit." What if we didn't like that closeness, and wanted to severe ourselves from God?
"For I am persuaded that neither death nor life, nor angels nor principalities nor powers, nor things present nor things to come, nor height nor depth, nor any other created thing, shall be able to separate us from the love of God which is in Christ Jesus our Lord."
Well, as long as we qualify as a "created being," that means that we are not able to separate ourselves from the love of God. And yes, hell is separated from the love of God. Very separated from all that is God.
"My Father, who has given them to Me, is greater than all; and no one is able to snatch them out of My Father’s hand."
No one. Not your mom, not your dad, not the devil, and not you are able to snatch yourself out of God's hand!
"Where can I go from Your Spirit?
Or where can I flee from Your presence?
If I ascend into heaven, You are there;
If I make my bed in hell, behold, You are there.
If I take the wings of the morning,
And dwell in the uttermost parts of the sea,
Even there Your hand shall lead me,
And Your right hand shall hold me."
Awesome!!! You can play hide and seek with God, and He'll still find you! You can run from God, but like a true-hearted lover, He will pursue you!
Even if a person wanted to lose their salvation (but why would they?) they couldn't. It just can't happen.