I would say belief and repentance is evidence of what the Father has done in giving us the Holy Spirit & faith when we heard the gospel for how we believe in Jesus Christ and are saved simultaneously when the Father did that. See post # 5 for scriptures testifying to that effect.
I would also like to point out that former believers are still saved just as those that fell away from the faith into apostasy or sinful living are still saved too,
but this is why we are to call them to go before that throne of grace to ask Jesus Christ for help to discern the lies that turn them away from Him as well as turn them away from the sins that have corrupted them.
Where do I get that from?
2 Timothy 2:10 Therefore I endure all things for the elect's sakes, that they may also obtain the salvation which is in Christ Jesus with eternal glory. 11 It is a faithful saying: For if we be dead with him, we shall also live with him: 12 If we suffer, we shall also reign with him: if we deny him, he also will deny us: 13 If we believe not, yet he abideth faithful: he cannot deny himself.
2 Timothy 2:18 Who concerning the truth have erred, saying that the resurrection is past already; and overthrow the faith of some. 19 Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, let every one that nameth the name of Christ depart from iniquity. 20 But in a great house there are not only vessels of gold and of silver, but also of wood and of earth; and some to honour, and some to dishonour. 21 If a man therefore purge himself from these, he shall be a vessel unto honour, sanctified, and meet for the master's use, and prepared unto every good work.
If anyone wants motivation to go to Jesus Christ for help, then consider the consequence for being left behind, & dying, and getting stripes.
2 Corinthians 11;7 (For we walk by faith, not by sight 8 We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord. 9 Wherefore we labour, that, whether present or absent, we may be accepted of him. 10 For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad. 11 Knowing therefore the terror of the Lord, we persuade men; but we are made manifest unto God; and I trust also are made manifest in your consciences.
1 Corinthians 3:10 According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon.
But let every man take heed how he buildeth thereupon. 11 For other foundation can no man lay than that is laid, which is Jesus Christ. 12 Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble; 13 Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. 14 If any man's work abide which he hath built thereupon, he shall receive a reward.
15 If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire. 16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you? 17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are.
Revelation 2:18 And unto the angel of the church in Thyatira write; These things saith the Son of God, who hath his eyes like unto a flame of fire, and his feet are like fine brass; 19 I know thy works, and charity, and service, and faith, and thy patience, and thy works; and the last to be more than the first. 20 Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols.
21 And I gave her space to repent of her fornication; and she repented not. 22 Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds. 23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works. 24 But unto you I say, and unto the rest in Thyatira, as many as have not this doctrine, and which have not known the depths of Satan, as they speak; I will put upon you none other burden. 25 But that which ye have already hold fast till I come.
Luke 12:40
Be ye therefore ready also: for the Son of man cometh at an hour when ye think not. 41 Then Peter said unto him, Lord, speakest thou this parable unto us, or even to all? 42 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? 43 Blessed is that servant, whom his lord when he cometh shall find so doing. 44 Of a truth I say unto you, that he will make him ruler over all that he hath. 45 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;
46 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. 47 And that servant, which knew his lord's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes. 48 But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more. 49 I am come to send fire on the earth; and what will I, if it be already kindled?
Hebrews 12:1Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us, 2 Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God.
3 For consider him that endured such contradiction of sinners against himself, lest ye be wearied and faint in your minds. 4 Ye have not yet resisted unto blood, striving against sin. 5 And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him: 6 For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth. 7 If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not? 8 But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons. 9 Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live?
10 For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness. 11 Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.