Another text which is helpful in this discussion is 2 Peter 2:18-22. "For, speaking loud boasts of folly, they entice by sensual passions of the flesh those who are barely escaping from those who live in error. 19They promise them freedom, but they themselves are slaves of corruption. For whatever overcomes a person, to that he is enslaved. For if, after they have escaped the defilements of the world through the knowledge of our Lord and Savior Jesus Christ, they are again entangled in them and overcome, the last state has become worse for them than the first. For it would have been better for them never to have known the way of righteousness than after knowing it to turn back from the holy commandment delivered to them. What the true proverb says has happened to them: 'The dog returns to its own vomit, and the sow, after washing herself, returns to wallow in the mire.'" I suppose one could argue that this is about people who are never truly regenerate but merely being part of the Christian community and giving a false profession. This is, however, not the obvious intent of the passage. They have escaped the defilements of the world and have known Jesus Christ. There is no where in the New Testament where these things would be claimed about an unbeliever. Knowledge of Christ implies saving knowledge. Some other passages which may be cited are, "You will be hated by all because of My name, but it is the one who has endured to the end who will be saved." (Matthew 10:22), "And let us not grow weary of doing good, for in due season we will reap, if we do not give up." (Galatians 6:9), "My brothers, if anyone among you wanders from the truth and someone brings him back, let him know that whoever brings back a sinner from his wandering will save his soul from death and will cover a multitude of sins." (James 5:19-20), "Now I would remind you, brothers, of the gospel I preached to you, which you received, in which you stand, and by which you are being saved, if you hold fast to the word I preached to you—unless you believed in vain." (1 Corinthians 15:1-2), and finally, "Because lawlessness is increased, most people’s love will grow cold. But the one who endures to the end, he will be saved" (Matthew 24:12-13)
So how does one deal with these and other passages that teach that a true Christian can lose faith and be lost eternally? Does this fit with a monergistic view of salvation or must we adopt a Wesleyan doctrine wherein man is responsible for his own perseverance? Observe what Pieper states about the Scriptural doctrine of perseverance. "What Scripture teaches on final perseverance may be summarized in these two statements: 1. He that perseveres in faith does so only through God's gracious preservation; the believer's perseverance is a work of divine grace and omnipotence. 2. He that falls away from faith does so through his own fault; the cause of apostasy in every case is rejection of God's Word and resistance to the operation of the Holy Spirit in the Word. This doctrine the Christian Church must maintain and defend on two fronts: against Calvinism and against synergism." (Dogmatics Volume III pg. 89)
Scripture does clearly teach that it is God who preserves man in faith. Observe a few statements which make this point clear, "Now to him who is able to keep you from stumbling and to present you blameless before the presence of his glory with great joy, to the only God, our Savior, through Jesus Christ our Lord, be glory, majesty, dominion, and authority, before all time and now and forever. Amen." (Jude 24-25)
"He who did not spare his own Son but gave him up for us all, how will he not also with him graciously give us all things?" (Romans 8:32)"And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ." (Philippians 1:6) "But by the grace of God I am what I am, and his grace toward me was not in vain. On the contrary, I worked harder than any of them, though it was not I, but the grace of God that is with me." (1 Corinthians 15:10)
It is clear that scripture teaches two things: 1. Man can fall away from the faith, and when he falls away it is blamed upon his own unbelief, not on God's decree. 2. God preserves man monergistically in faith. Sanctification is wholly His work. We must necessarily hold to both since the scripture teaches both. There is one more set of texts left to look at, those used to defend perseverance which reference election.
Romans 8 is a classic defense of the doctrine of perseverance. "For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified." This is often called the "golden chain of salvation." This is an unbroken chain. All whom God foreknew end up finally glorified. There is no possibility here of a foreknown, elect, justified man falling away and failing to be glorified. This does not, however, support the doctrine that man cannot fall away from faith. It shows that those whom God elects will not fail to be glorified. The Lutheran confessions are clear on this point. This does not imply however, anything about other men being regenerate and falling away. 1 John 2:19 can be explained in the same way.
Thus we now see three things clearly taught in scripture.
1. God sanctifies man monergistically, through the means of word and sacrament.
2. Some men can and will fall away from the faith through neglecting word and sacrament, and willingly disregarding repentance and faith.
3. All of God's elect will be infallibly saved.
Thus if man perseveres it is entirely God's work. However, if a man falls away, it is entirely his own fault.
If perseverance is merely an outcome of election, as many Calvinists including James White have explained it, then we agree. However, that does not mean that no others can be truly regenerate and then fall away