Luke 19:10, John 3:16, John 3:17, John 1:29, John 4:42, 1Tim. 4:10, Heb. 2:9, Rom. 5:6, Rom. 5:18, 1 John 2:2, Is. 53:6, 2 Pet. 2:1, Titus 2:11
All of these verses teach that Christ died for all of the sins of the entire world. That is, He paid the penalty for all of our sins… even for the sins of the unbeliever.
The unbeliever is not sent to Hell to pay for their sins. They go to Hell because they did not place their trust in Christ. Sins can never be an issue to God because He sent his Son to pay the penalty for sin at the cross. Punishing someone in Hell for sins that Christ was already punished for (as a substitute) is a simple case of double-jeopardy and violates God's absolute and perfect Justice. Either Christ died to pay the penalty of our sins, or He didn't. The Bible clearly says that He did, and that he paid the penalty for everyone's sins.
To reinforce this, consider John 3:18 and John 3:16, which read as follows:
John 3:18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
John 3:36 He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
As you consider these, recall that "believe" here is from the Greek "pisteuo" which means to trust in or rely on. So, In both verses, the person who places their trust in, or relies on Christ for their salvation is not condemned and has everlasting life. Again… how long does "everlasting life" last? It lasts forever. So while "pisteuo" may appear here in the present tense, the fact that trusting in Christ now (in the present) results in eternal life. There is no room here for having this eternal or everlasting life taken away, because once again, eternal life lasts forever.
But back to the main point of this post… the unbeliever is condemned not for their sin. Sin is never mentioned in these verses. The only thing mentioned is that the unbeliever does not trust in, does not believe in, Christ. That is the issue.
Now to reinforce that even further, consider this passage in Revelation 20:12-15 considering the final judgment:
And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works. And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works. And death and hell were cast into the lake of fire. This is the second death. And whosoever was not found written in the book of life was cast into the lake of fire.
Notice that there is no book of sins here. Sins are not counted, tabulated nor even mentioned in this passage. God's 'database' of believers is the "book of life." People whose names have been blotted out of the book of life never placed their trust in Christ, and on that basis they are condemned. Sins are never mentioned at the final judgment, they are not an issue. The Greek word for sin is "hamartia" and it does not appear in this passage.
Remember Psalms 103:12:
As far as the east is from the west, So far hath he removed our transgressions from us.
But what about "works"? It says people are judged according to their works, right? Doesn't that mean sin?
I don't know why it would, considering all those verses which say clearly that Christ died for all sin. The Greek word for "works" is "ergon"… this does not encompass sin by any stretch. Sins are gone, dealt with. Paid in full. What's happening in this passage in Revelation is that unbelievers are being judged on their own righteousness. The works that the unbeliever did which were good are measured up against God's perfect righteousness and, unfortunately, the person won't measure up because, as Isaiah 64:6 says, all our righteousnesses are like filthy rags. And since the person doesn't wear Christ's righteousness, (not in the book of life) they are cast into the lake of fire.
The point is, sin is no longer an issue. This is not to say that we should sin or that we should not try to avoid sinning. But sins were paid for and are no longer an issue. Consider 1 John 2:1, which says:
My little children, these things write I unto you that ye may not sin. And if any man sin, we have an Advocate with the Father, Jesus Christ the righteous
If we sin (and we will, in spite of our efforts to the contrary) Jesus Christ is our advocate. It doesn't say how many times we're allowed to sin, it doesn't say that after x number of sins Christ will no longer be our advocate. None of that. All sins were paid for and when you grab ahold of that and choose to believe it, eternal security becomes that much more obvious.