A Question I Was Asked:

"Once a person is born again but continues to sin, or falls back into sin through, for example, ungodly sexual behavour, alchoholism etc., (with the complete knowledge that this is sin and is unpleasing to God), then does not that person lose their salvation?"

My Reply:

Your question initially seems very reasonable, humanly speaking, and yet, careful consideration shows that the question and perspective is biblically and spiritually erroneous.

For a start, you say, "Once a person is born again but continues to sin..." but a person who is truly 'born again,' or, 're-born from above' will not then "continue to sin" (as you put it), in the same old way. In contrast to your approach, the apostle John writes, 'For everyone born of God overcomes the world...' (1 John 5:4a, NIV). Yes, none of us ever fight entirely free from sin in this present life, yet without question, true believers who are reborn from above and come under the grace of God , do not - thereafter - have sins of weakness and temptation credited to their account; rather, Christ's righteousness becomes imputed to them, since they then become covered by the grace of God and clothed in the righteousness of Christ (Romans 4: entire chapter). So, with respect, your opening comment is already in error.

Secondly, your approach is wrong in a much broader way simply because you are looking at this matter from a purely human perspective, but this whole matter is of God - not of human beings! We are not here discussing some purely human psychological theory put forward by some eminent professor, we are considering something we could not even begin to understand - apart from the Word of God. This is divine revealed knowledge which no scientist, anthropologist or psychology professor could ever have come to understand - in fact, they still don't understand it because the knowledge is spiritually discerned. It is obvious then that we can only consult Holy Scripture in order to try to understand a little more.
You seem to imply that human beings can make or break the grace of God by their behaviour but this is not scriptural. God is at work in this entire process and so we must carefully consult Scripture for the true perspective on this.

Once we do refer to Holy Scripture we find that those who are born again receive the Holy Spirit as 'the earnest of their inheritance' (as the KJV puts it), that means that the Holy Spirit which God grants is their 'down-payment' on Eternal Life! God actually grants us a tiny bit of Eternal Life through the Holy Spirit, so when we receive that Spirit, God guarantees that we will eventually inherit Eternal Life, we become God's own children in a full spiritual sense (we are all God's children in a physical sense). I REPEAT: This becomes a matter of a DIVINE GUARANTEE! Scripture is quite plain that these people cannot be snatched out of God's hand (John 10:27-30, also note John 6:37-40). I cover this matter at depth in answer to an earlier question Here.

It reached the ears of the apostle Paul that certain people at Rome were saying that true believers could still fail to enter God's kingdom, Paul's answer to this can be read through Romans 8!! I recommend you read that entire chapter; Paul is saying that no matter what may befall true believers upon this earth, their salvation is assured. These people are simply not going to "fall back into sin" if they are truly 're-born from above.' If such people completely fall away (and you suggest extremes of alcoholism and sexual depravity), then such people were never 're-born from above.' I stress 'completely' because we should all understand that every single Christian upon this earth will go through trials, including spiritual trials and 'backsliding' phases - during some of these phases some of us are just not close enough to God and we suffer because of it. But God does not then behave in a capricious or whimsical manner (as people probably would!), and proceed to cancel our salvation, because that is the subject of a divine guarantee.

To be 'born again' (I tend to prefer the expression 're-born from above' which is just as faithful to the Greek), is to come under the full grace and spiritual protection of God. He puts His seal on us.

Some people believe that only true believers can commit the unpardonable sin: this is actually a most grievous spiritual error which effectively makes God out to be a liar!! The only time Jesus discusses the unpardonable sin in the New Testament He makes His point in connection with certain of the Jewish religious authorities who accused Him of acting through the power of demons (carefully consult Matthew 12:22-32 and Mark 3:29-30). He strongly implies that certain of those religious leaders had committed the unforgivable sin by their continual opposition to the Holy Spirit who powerfully worked through Him! Since those Pharisees were (plainly) not converted, then the unpardonable sin is obviously not something which only true believers can commit!

I will close this by quoting just a few of Paul's words in Romans 8; he was seeking to reassure the Christians at Rome that their salvation was not still in jeopardy after everything they had already suffered,

'For those God forekew he also predestined to be conformed to the likeness of his Son, that he might be the firstborn among many brothers.
And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
What then, shall we say in response to this? If God is for us, who can be against us? He who did not spare his own Son, but gave him up for us all - how will he not also, along with him, graciously give us all things?
Who will bring any charge against those whom God has chosen? It is God who justifies,
Who is he that condemns? Christ Jesus who died - more than that, who was raised to life - is at the right hand of God and is also interceding for us.'
(Romans 8:29-34, but please read the entire chapter!).

So the problem with the thrust of your question is that you speak of those who are "born again" but you then make certain comments which are not applicable to those who are truly born again.

Any further questions in this area which I may have neglected to address here should be covered in:
If a Christian Commits a Serious Sin Does This Somehow Prove That He/She Was Never Really a Christian?
Once Saved, Always Saved?
What is the Unpardonable Sin?
Robin A. Brace, 2007.