Some theological issues can be studied; others have to be wrestled with. The question of whether or not a man or woman who is saved will always be saved falls into the latter category.
We have two seemingly contradictory pictures in the Bible. On the one hand there are the commands to watch out lest we fall: "Therefore, dear friends, since you have been forewarned, be on your guard so that you may not be carried away by the error of the lawless and fall from your secure position." (2 Peter 3v17) or "Work out your salvation with fear and trembling" (Philippians 2v12). And there are example in the Bible, and from the church throughout the ages, of people who having once professed to be Christians, and seemed to walk with God, then turned away from it all.
And yet on the other hand we have the statement of Jesus: "And this is the will of him who sent me, that I shall lose none of all those he has given me, but raise them up at the last day. For my Father’s will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise them up at the last day." (John 6v39-40).
We find a promise of Christ, that he will lose none of those given to him by the Father, seemingly at odds with both other verses in the Bible and our experience of seeing people fall from faith. This requires us to study further for a logic principle of the infallibility of the Bible is that Scripture cannot contradict Scripture.
Correctly understood, the doctrine of the perseverance of the saints (to use the theological terminology) is of great comfort to the Christian, providing as it does iron cast assurance of lasting faith. When we walk through our valleys of the shadow of death we need to have an anchor firm and secure in God's promise to protect us to the end. When we fall into sin we need to know that our faith is not lost. We need an assurance of eternal salvation to face the trials and struggles of life, our own inherent weakness and the temptations that assail us.
To proceed we will look first at the grounds of our perseverance and secondly the means by which this is achieved.
Our certainty of perseverance is rooted in the will of God and not of man. This is no surprise, for what a feeble thing the will of man is! How could we ever trust such a fickle thing? But the will of God is eternal and unchanging and a firm foundation for us. The ground for our perseverance is bound up in the Trinity - the love of the Father, the work and person of Jesus Christ and the indwelling of the Holy Spirit.
The Love of the Father
"Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ. For he chose us in him before the creation of the world to be holy and blameless in his sight. In love he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will – to the praise of his glorious grace, which he has freely given us in the One he loves." Ephesians 1v3-6.
The starting point for the doctrine of the perseverance of the saints is the Father's electing love. As it says above "In love he [God the Father] predestined us for adoption..." So immediately we ask: can God's loving sovereign choice fail? Can his will be undone? If God chose us in eternity past will he not save us for the eternity to come? The Puritans had the concept of the golden chain of salvation, best expressed in Romans 8v30: "And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified." The golden chain cannot be broken, those God has predestined will see it to the end stage of being glorified. There is no footnote to this verse, no exception, no breaking of this golden chain.
The Work and Person of Jesus Christ
"Now there have been many of those priests, since death prevented them from continuing in office; but because Jesus lives for ever, he has a permanent priesthood. Therefore he is able to save forever those who come to God through him, because he always lives to intercede for them." Hebrews 7v25
When it comes to the priestly work of Jesus Christ there is no better book to turn to than Hebrews. And here we find the truth that Jesus is "able to save forever" because he is a permanent priest who "always lives to intercede for them". See the connection: Christ saves us forever because he is in heaven interceding for us. In his high priestly prayer Jesus prays: "Father, I want those you have given me to be with me where I am, and to see my glory." John 7v24. Shall this prayer not be answered? Did Christ die in vain? Does he not pray in heaven what he prayed on earth? Did Jesus not assure Peter that he has prayed that Peter's faith will not fail? And though Peter denied Christ did his faith not remain intact?
As Jesus says in John 10v28: "I give them eternal life, and they shall never perish; no one will snatch them out of my hand." It is not possible for a believer to be snatched out of the hand of Jesus. It is not possible to snatch yourself out of his hand. "What shall separate us from the love of Christ?" Paul asks in Romans 8 and concludes that nothing can.
The Indwelling Holy Spirit
Back to Ephesians 1: "When you believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession – to the praise of his glory." (v13-14)
Once again, notice the train of thought: when we believer we are given a seal, the Holy Spirit, who guarantees our inheritance. Can a guarantee of God fail? Is his word not more trustworthy? John Flavel had a wonderful way of looking at it: when we believe the Spirit secures heaven for us and he immediately brings much of heaven to our souls.
The ground for our perseverance is in the electing love of the Father, the work and person of Jesus Christ and the indwelling of the Holy Spirit. Well then does John write: "And his commands are not burdensome, for everyone born of God overcomes the world. This is the victory that has overcome the world, even our faith." (1 John 5v4).
This is one half of the picture. It is the starting point of the doctrine of the perseverance of the saints. But it is not the end point. But it does answer some important questions. The first is that those who fall away were not saved in the first place. For if they were saved they would have persevered. The logic is best expressed like this:
1. The elect cannot fall away (John 6, John 10, etc).
2. Some who profess to believe fall away.
3. Hence, professors who fall away are not elect.
Understood this way surely this becomes a ground for laziness? If I think myself elect and I therefore know heaven is a certainty then why bother fighting the world, the flesh and the devil? Why can't I just sit back and wait for heaven to come to me?
This represents a poor understanding of the intersection of divine sovereignty with human responsibility. To see where this goes wrong we must also answer the question: by what means is perseverance administered to God's people?
God has purposed to save his elect to the uttermost. The grounds for our perseverance is in the three persons of the Godhead. But the means are in our hands, by God's appointment. These means are the "means of grace"; so called because they are the "outward and ordinary means by which Christ communicates to his church the benefits of his mediation". These means are the Word, prayer, the sacraments (Lord's supper and baptism). If we don't make regular use of this means then we will struggle. To quote from a Puritan Theology "God will preserve us by his grace, making our use of the means of grace effectual to the accomplishment of his purpose." (p616).
We can now tie in the verses quoted at the very start. "Work out your salvation with fear and trembling" is immediately followed by the verse "for it is God who works in you to will and to act in order to fulfil his good purpose." (Philippians 2v12-13). This is in terms of justification and sanctification. Christians work at being holy because through Christ we are already declared holy before God. Using identical logic: we work at our perseverance by diligently using the means of grace because we know that God has purposed to preserve us to the end. Our work is grounded in his eternal purpose.
The comfort of a Christian is that his salvation is secure. No one will pluck him from the hand of Christ. Not one promise of God's can fail and there are many promises of God relating to the assurance of our eternal salvation. The Father elected us with his eternal love, Jesus Christ the Son intercedes for us in heaven, saving the elect to the uttermost and the Holy Spirit dwells in us, guaranteeing our inheritance of heaven.
No wonder Paul writes: "I am sure of this, that he who began a good work in you will bring it to completion on the day of Christ" (Philippians 1v6). It is our duty to join in this good work, to make use of the means of grace, to work out our salvation with fear and trembling, to draw near to God, to meet with his people regularly and to put sin to death. This is all done in the hope, confidence and comfort that heaven is secured for us, our salvation rests in Christ's hands and he will see all his people saved.
As that well known hymn goes:
"No guilt in life, no fear in death,
This is the power of Christ in me;
From life's first cry to final breath,
Jesus commands my destiny.
No power of hell, no scheme of man,
Can ever pluck me from His hand:
Till He returns or calls me home,
Here in the power of Christ I'll stand."