But this is not true, and neither is this biblical. When Jesus died on the cross, He became the final and complete sacrifice for all our sins—without exception. Jesus did not die for just some of our sins but for all of it, the past, present, and future!

1 John 5:18 (NKJV)

We know that whoever is born of God does not sin; but he who has been born of God keeps himself, and the wicked one does not touch him.

The verse above does not say that a Christian never commits an act of sin but that they do not continue in the course of sin – refusing to confess and repent of their sins. 

If someone has been born again, there will always be something in their conscience that draws them back to repentance every time they sin. This is why God gave us the Holy Spirit to empower us to complete the race and become more like Christ (also known as the process of sanctification) and so that we may not be deceived by the evil one.

We tend to tell ourselves that there is no sin in us, but the reality is that we are still in a fallen world, and our body is weak, as also expressed by the apostle John;

1 John 1:8 (NKJV)

If we say that we have no sin, we deceive ourselves, and the truth is not in us.

The scriptures make this truth clear that even though we are redeemed, we would inevitably continue to sin to some degree. Therefore, If it really were up to us to generate enough strength to persevere and guarantee our future salvation, then we would indeed have very little hope of persevering.

Two other interesting questions that are often asked in relation to this matter are as follows;

(1) What about Christians who continuously sin and live an immoral lifestyle? 

(2) What about Christians who later reject the faith and deny Christ?

The answer to these questions is best found by asking, “who are Christians?” According to the Bible, a true Christian will not choose to live an immoral lifestyle.  

1 John 3:6 (NKJV)

Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.

Concerning the second question, the Bible declares that anyone who departs from the faith demonstrates that they were not a Christian in the first place.  

1 John 2:19 (NKJV) 

They went out from us, but they were not of us; for if they had been of us, they would have continued with us; but they went out that they might be made manifest, that none of them were of us.

In conclusion, true Spirit-filled Christians will not choose to live an immoral lifestyle, nor will they reject the faith and deny Christ. On the contrary, such actions are a sign that they were never redeemed. 

God is gracious and just. And if you have put your faith in Jesus Christ and honestly believe in Him, then He is faithful to see you through and complete the good work He began in you.  

Philippians 1:6 (NKJV)

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;

Our assurance of our salvation should rest in the fact that Jesus promises to intercede for us daily as our Great High Priest and that our future salvation rests in the confidence that God will keep His promises to preserve us through the workings of His Spirit.