Someone asked me a question yesterday. If somebody was put out of your church due to unrepentant sin, then came back repentant later on, would I re-baptise them or not? I thought that was an interesting, worthwhile question. An interesting, worthwhile question to which the short answer is ‘no’.

My friend asked, ‘is that because their returning to the Lord and his people suggests that they were saved?’ Potentially, yes. I tend to view baptism as an affirmation of belief on the part of the church at the beginning of the Christian life. Granting communion in membership is the ongoing affirmation of belief on the part of the church throughout one’s Christian life. This will continue to be granted so long as the person remains in membership of the church.

The only thing that will put that person out of membership of the church is unrepentant sin. Note, not sin in general – even very serious sin – but unrepentant sin. That means, if somebody repentantly returns to the church having been removed from membership because of their previous unrepentant sin, there is no need to re-baptise them as though they were never a believer. Though the length of time might be longer than that of those who repent without being removed from church membership, the repentance in the end suggests this is a believer who wandered away and has returned.

My friend asked, ‘is that, then, the difference between backsliding and apostasy?’ I guess so. Apostasy is a committed departure from the faith. It is not just a matter of unrepentant sin (though it may start off as such), it is a committed turning away from the faith. Backsliding, by contrast, is the action of someone who has not necessarily renounced the faith entirely but who has determined to pursue their sin rather than Jesus. Both the apostasizer and the backslider may be put out of the church and both must be treated as unbelievers. The difference is that the backslider, eventually, returns to the Lord and his people. Indeed, we only really know the difference at the point the backslider has returned and repented.

The term ‘backslider’ is applied to those who have made professions of faith, maybe even continue to claim they trust in Christ, but whose lives are such that they undermine their own profession and have been put out of the church (or never accepted into one) because of their unrepentant sin. But this is not right. We cannot call such a person a backslider unless and until they have actually repented of their sin and returned to the Lord. If they do that, we might consider them to have backslidden, having now returned to Christ. But if they do not, they are no more a backslider than anyone else who rejects Christ; they are simply unbelievers.

This is important to grasp. All too often we convince ourselves that people are saved when, in reality, all the evidence points to the fact that they are not. We seem to want to treat markedly different those who have professed faith once, but have now renounced that profession – whether directly saying as much or simply by their lifestyle continuing in unrepentant sin – to those who have never professed faith at all. But in the end, both must be considered as unbelievers unless and until they repent and trust in Christ.

The last thing we should want to do is comfort people in their sin. When the Bible is clear that continuing in unrepentant sin leads to Hell, we do nobody any favours when we pretend that their profession still holds despite every evidence to the contrary. We do better to have clarity about where people stand before the Lord. In the end, ‘once saved, always saved’ is not a biblical doctrine; the Bible teaches the perseverance of the saints and these two things are not the same. The best evidence of true conversion is pressing on with Christ until the end and that is not the same as having made a profession at some point in the past. That is not to say we cannot be sure of our salvation; it is to say if we turn away from Christ and continue in sin such that we are removed from membership of the church, we can have no assurance until we repent.