This scripture in 2 Peter 3:14 is a proof text. It is providing proof that born again believers who are waiting for Christ’s return and by faith are looking forward to God’s promise of a new heaven and a new earth are being warned of the danger of being found with unrepentant sin. It is proof that believers can still sin and that there is still a danger in sinning.

2Peter 3:14
“Wherefore, beloved, seeing that ye look for such things, BE DILIGENT THAT YE MAY be found of Him in peace, without spot, and blameless.”

If a believer commits a sin they are no longer spotless, blameless or forgiven (at peace with God). At the point of sinning we have acquired blame for breaking God’s law, we become guilty again and in need of Jesus Christ’s intercession, mediation and forgiveness. That’s because we now have a spot on our previously clean record from when we were previously forgiven.

When Peter says that we must be diligent, he means that we must continually be mindful to keep God’s commandments; and to the very best of our sincere abilities, that we also resist sin putting it away. But and if when we do sin, we are also diligently confessing, repenting and asking forgiveness of it just like Jesus taught us to do in the Lord’s Prayer.

When we are diligent to do all these things then we can have absolute confidence and faith that we are forgiven, at peace with God and without spot (without sin), no longer guilty but blameless and cleansed.

There are many other scriptures that fit this proof text and here are a few of my favorites.

1John 2:1-6
“My little children, these things write I unto you, that ye sin not. AND IF ANY MAN SIN, we have an advocate with the Father, Jesus Christ the righteous: And He is the propitiation FOR OUR SINS: AND NOT FOR OURS ONLY, but also for the sins of the whole world. And hereby we do know that we know Him, if we keep His commandments. He that saith, I know Him, and keepeth not His commandments, is a liar, and the truth is not in Him. But whoso keepeth His word, in him verily is the love of God perfected: hereby know we that we are in Him. He that saith he abideth in Him ought himself also so to walk, EVEN AS He walked.”

1John 1:9
“If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.”

Here’s another that proves born again believers can lose salvation by not being diligent.

2Peter 2:20-21
“For IF AFTER THEY HAVE ESCAPED the pollutions of the world THROUGH the knowledge of THE LORD AND SAVIOUR JESUS CHRIST, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.”

Also we have this parable where Jesus warns us about the servant who returns back to unrepentant sinning. Jesus defines what a faithful servant looks like and what an unfaithful servant looks like. Jesus is pointing out that faithfulness and salvation are not being determined by a profession of faith only, but also by the actions of that servant and what he chooses to do.

Luke 12:42-46
“And the Lord said, Who then is that faithful and wise steward, whom his lord shall make ruler over his household, to give them their portion of meat in due season? Blessed is that servant, whom his lord when he cometh shall find so doing. Of a truth I say unto you, that he will make him ruler over all that he hath.

BUT AND IF that servant say in his heart, My lord delayeth his coming; and shall begin to beat the menservants and maidens, and to eat and drink, and to be drunken; The lord of that servant will come in a day when he looketh not for him, and at an hour when he is not aware, and will cut him in sunder, and will appoint him his portion WITH THE UNBELIEVERS.”