There is great debate among Christians whether a believer is secure in their salvation or whether it can be lost or forfeited after obtaining it. Although there are opposing viewpoints on the subject, with compelling arguments and strong Scriptural support for both positions, the crux of the dispute is whether someone who “loses or forfeits” their salvation ever possessed it at all. In other words, could someone who claimed to be born again and exhibited good works over a long period have possessed genuine saving faith if they renounced it later?
Believers on both sides of the debate acknowledge salvation is a gift from God offered freely to all. They believe God imputes it solely based upon faith in Jesus for what He accomplished and provided on the cross. They also accept that there is no other vehicle through which God imparts His saving grace to sinners outside of faith itself.
Both sides further acknowledge that individuals receive God's gift of salvation when they place their faith and trust in Jesus for what He accomplished for them on the cross. They agree that sinners cannot earn salvation by doing good works or participating in religious ceremonies or ordinances. They accept Jesus' work on the cross as sufficient to provide everything necessary for salvation and redemption, and they assert the only thing required for it to be credited to a sinner is faith.
Both sides also seem to agree on the issue of sin itself within the lives of professing believers. They agree that when a believer sins or struggles in a particular area of it, they do not lose their salvation. Instead, they have broken their fellowship with God and need to confess their sins to have their fellowship restored. On the contrary, if a professing believer habitually and continually practices sin—treating God’s grace as a license for it—both sides agree this person does not, most likely, possess salvation.
The disagreement over whether apostates originally possessed salvation ultimately stems from their inability to see the Holy Spirit's presence inside a person’s heart. Without access to this indisputable evidence of salvation, believers can only examine external evidence, which can be deceiving.
Supporters of the “security of the believer” position argue that a person who renounced their faith never possessed salvation, ever. They assert these people simply offered lip service and modified their external behavior accordingly. Those who hold this view also claim genuine salvation cannot be altered or undone once received. They contend that the verses appearing to support the idea of salvation being lost or abandoned only refer to those who never possessed it.
Supporters of the “insecurity of the believer” position argue that a person who renounced their faith may have possessed salvation initially, as evidenced by their good works and acts of obedience to God. However, later, they willfully chose to reject Jesus and forfeited their salvation by their apostasy. Supporters of this position also argue that verses supporting a believer’s security refer only to those who continually trust Jesus for their salvation and never stop.
Regardless of which position someone leans toward, the fact remains that personal faith in Jesus is the only requirement for sinners to receive salvation and redemption. Likewise, faith is the only vehicle by which Jesus can impart His salvation to sinners. Aside from those facts, I doubt the argument will ever be settled between the two opposing sides.
I hope this information has been helpful and informative for you on this topic. God bless you as you contend for the faith!