The five-point Calvinist view of eternal security is enumerated in the last letter of the TULIP acronym, P standing for the doctrine of the Perseverance of the Saints. In line with the totality of Calvinist theology and its focus on God’s sovereign actions, this would perhaps be better entitled Perseverance of the Lord since it is He who keeps the believer until their moment of glory. These believers may backslide and sin but this view states that the believer cannot fall away completely from grace and they will persevere until the end and be saved.
Eternal security in Calvin’s theology must be understood in the context of the entire framework, as all of the points are logically connected. The elect (the only humans who God chooses to redeem) will be the recipients of the persevering power introduced by the indwelling presence of the Holy Spirit. These believers will be kept in the power of the Spirit and are eternally secure. Calvin words it this way:
God, who is rich in mercy, from his immutable purpose of election, does not wholly take away his Holy Spirit from his own, even in lamentable falls; nor does he so permit them to glide down that they should fall from the grace of adoption and the state of justification; or commit the “sin unto death,” or against the Holy Spirit; that, being deserted by him, they should cast themselves headlong into eternal destruction. So that not by their own merits or strength, but by the gratuitous mercy of God, they obtain it, that they neither totally fall from faith and grace, nor finally continue in their paths and perish.
Scripture references are easy to locate in support of this idea of perseverance. The unbroken chain of salvation found in Romans 8:29-39, so glorious that it leads Paul to doxological joy, is often put forth as the only passage necessary in support of this doctrine. Jesus gives the promise voice in John 10:27-29 where He recites the covenant using a shepherd metaphor; His sheep know Him and they have been given eternal life by Him. They face no danger of perishing nor can any force or event challenge that status (cf: Rom 8:38-39). Divine purpose is described in the introductory lines of Ephesians (Eph 1:3-14) where the unbroken chain of salvation is again rehearsed. The Elect were chosen by God before creation for redemption therefore that status cannot be broken; it must come to pass that they will be saved. Further texts [1 Pet 1:3-5, Phil 1:6, Heb 7:25, et. al.] cited by the Calvinist would cement the same point: since God has elected certain of humanity from among the fallen to be the recipients of eternal life and these individuals are promised that life, it necessarily follows that this salvation is permanent. If they could somehow lose this salvation, God’s promise would not be effectual.
Calvinist theologians also infer the doctrine of perseverance from the study of other doctrines. For example, believers enjoy a union with Christ. In John 15:1-11, the Elect are shown to be united with Christ and living through the life force that flows from Him. No force can divide this union, thus removing a believer from the Body so the promise inevitably follows. The doctrine of being born again anew also points to the promise. In 1 John 3:9 John writes:
No one who is born of God will continue to sin, because God’s seed remains in him; he cannot go on sinning, because he has been born of God.
If salvation could be lost, regeneration would have to be undone and the believer visited by spiritual death once again. This idea would challenge the power of the Holy Spirit who, indwelling the believer, would have been unable to keep the individual. Perseverance can also be implied by the doctrine that the believer can have assurance of his or her salvation (Heb 6:11, 10:22, 2 Pet 1:10). John once again offers a text that follows his list of evidences that God has given eternal life followed by these words, “I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.” (1 John 5:13)
There is a critique commonly spoken against this position that is rooted in the sovereign choice, maintenance, and glorification of the Elect by God, wholly apart from the will or actions of man. Given such assurance apart from their own will or choice, humankind is tempted to live a morally lax life assured that regardless of their sinfulness or even devotion to Christ, their ultimate salvation is guaranteed in the promise of God. As Demarest writes (The Cross and Salvation, pg 444) “The popular saying, “Once saved, always saved” is misleading, for it may suggest that believers will be saved irrespective of how they live. The Calvinist response is to initially agree that regenerated and justified believers may indeed lapse in their faith, resist God, and fall into sin for a period but their unbelief and resistance is fleeting, rather than incorrigible and final. God deals graciously and patiently with genuine Christians who lapse in their faith. Spurgeon commented that there is a kind of faith that appears lively but never personally commits to Christ and obeys the gospel. It is these ‘supposed’ or ‘outward appearing’ Christians that are at risk of finally falling away. He writes of the assurance implicit in the promise, regardless of temporary lapse:
We believe that God has an elect people whom He has chosen unto eternal life, and that truth necessarily involves the perseverance in grace. We believe in special redemption, and this secures the salvation and consequent perseverance of the redeemed. We believe in effectual calling, which is bound up with justification, a justification which ensures glorification. The doctrines of grace are like a chain– if you believe in one of them you must believe the next, for each one involves the rest; therefore I say that you who accept any of the doctrines of grace must receive this also, as involved in them.
The classical Calvinist position is perhaps the easiest to examine as it simply rests on the promise of the Lord. Eternal security rests in the sovereign will of God; He chose some for eternal life and because of this fact, nothing can interfere with that promise coming to fruition. Jesus explains it simply:
For I have come down from heaven not to do my will but to do the will of him who sent me. And this is the will of him who sent me, that I shall lose none of all that he has given me, but raise them up at the last day. (John 6:38-39)