“Some who believe that Christians are eternally secure give their doctrine the slogan ‘once saved, always saved,’ but that slogan is very misleading. The slogan suggests that once persons make a decision for Christ, they can then go off and do their own thing, fully confident that no matter what they do or how they live, they are ‘safe and secure from all alarm.’ That simply is not biblical.
The new birth, to be sure, is an event. In other words, at some point in your life, the Holy Spirit moves and creates new life in your soul. But salvation is more than that. Justification, too, is a one-time declaration, but salvation also involves a process of, over time, becoming righteous, which is called sanctification.
Sanctification is the Christian life, the daily pursuit of God and the transformation of the heart, mind, and will. Our priorities and our view of life are drastically altered, revolutionized, and reversed. We did not cooperate in our justification. But we must cooperate with God in our sanctification.
Some Christians have the idea that they must sit back and let the Spirit do everything. But…the process toward maturity in Christ is not based on a passive view of life. Another way of saying sanctification is ‘taking the bull by the horns.’ We do not wait for the Holy Spirit to perform some supernatural number on our lives: he already has done this for us! We actively pursue holiness and Christ-centeredness in our lives, recognizing that the same One who commands us to work, persevere, and obey gives us the supernatural ability to do so. Just do it! You do the work; but recognize that, if the work is done, God has done it in and through you.
So then, when we speak of ‘once saved, always saved,’ we are not taking into account the full scope of salvation. We have been saved (justified), we are being saved (sanctified), and we will one day be saved (glorified). You cannot claim to have been ‘saved’ (justified) unless you are being sanctified. Jesus Christ is Savior and Lord.
Jesus made it plain throughout his ministry that one could not become his disciple (and, therefore, could not receive eternal life) unless that person was willing to ‘take up his cross daily’ and follow Jesus. The New Testament emphasizes denying yourself, dying to sin, and deferring to others.
These terms identify a concept that is not in vogue today. When even many church leaders are telling people to ‘believe in yourself’ and are preaching a gospel that is more concerned with fulfilling our desires than God’s, we have difficulty falling unreservedly into the arms of the Savior in whom we find our only confidence. But of course, we cannot ever tailor-make the gospel to fit our self-serving expectations.
Romans 8:30 makes clear the chain of salvation, a chain whose links cannot be broken: ‘And those he predestined, those he also called; those he called, he also justified; he justified, he also glorified.’ Can one be predestined, called, justified, and lost? This verse teaches us that when God starts something, God finishes it. Did you grant yourself salvation? Did you gain it yourself in the first instance? No, salvation was a gift. Remember, God justifies and condemns: ‘Who will bring any charge against those whom God has chosen? It is God who justifies. Who is he that condemns? (Rom: 8:33-34). . . Since God initially gives us the grace to believe in him and to turn from self, why would he not give us the grace to keep on trusting in him?. . .
We have the responsibility to ‘go onto maturity'(Heb. 6:1). So we are responsible to persevere, but not for our perseverance. We are responsible to be saved, but not for our salvation.
To lose our salvation, we would have to return to a condition of spiritual death. Of what sort of regeneration would the Holy Spirit be the author if those whom he has resurrected and given eternal life are capable of dying spiritually again? ‘Well, can’t you commit spiritual suicide?’ one might ask. Not if we take seriously the claim of 1 Peter 1:23: ‘For you have been born again, not of perishable seed, but of imperishable’.”
– Michael Horton, Putting Amazing Back into Grace, p. 206-208, 210