by G. K. Beale, taken from A New Testament Biblical Theology, pp.865-870.
The Implications for "Assurance" in Relation to Ongoing Christian Living as Transformed New-Creational Life
One of the consistent conclusions throughout this section is that those who have begun to be a part of the new creation will inevitably progress and grow in this new-creational life, which means that they will grow in godly living. This is not an option. It is not something that may or may not happen. All the passages studied above (and many others) assert that true believers will necessarily and increasingly be characterized by obedience. This may happen slowly, but it will come about surely, as Eph. 2:10 asserts: "For we are His [new] creation, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them."
We saw in an earlier chapter on already-not yet justification that those who have been justified by faith in Christi still need the badge of good works at the time of the final resurrection and judgment in order to gain entrance to the new heaven and earth. This conclusion is at odds with a popular notion that the only thing needed for salvation is belief, and that good works may or may not follow such belief. Accordingly, this popular viewpoint tends to construe the idea that believers must be characterized by good works as "salvation by works," whereby people earn their salvation by doing more good deeds than sinful ones.
In response, in that earlier chapter I explained that the ultimate basis of our justification comes by faith in Christ's work, and that good works are necessary evidence that vindicates us on the last day as having truly been justified. Thus, the necessity of works for final salvation does not have to include the idea of earning salvation by doing good deeds. The evidence of the present chapter similarly highlights that for someone to be considered a true part of the beginning new creation, that person needs to reflect a change from an ungodly lifestyle to a godly one, making progress in righteous living over the course of subsequent life.
But this anthropological portrayal raises a question: if works are a necessary badge for Christians, how many good works does one need in order to be assured of salvation? Of course, Scripture gives no formula to answer this question. However, Paul does give a broad "black and white" answer. For example, in 1 Cor. 6:9-11, Paul says,
Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God. Such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.
After coming to faith, people should not remain in the sinful lifestyle that characterized their pre-Christian life. For example, an adulterer or a homosexual or a drunkard or a swindler, once having become a Christian, should decisively stop living in those kinds of sins. Such people do not become perfect, but they do repent from committing the sins to which they were in bondage. They still sin, but the power of their former sinful bondage has been broken. Because their former, fallen heart has been removed and a spiritual heart has been put in, they now increasingly desire to please God by obeying him instead of pleasuring themselves. But they do not perfectly obey God, since there are still unruly desires and sins to which they succumb. Nevertheless, perhaps slowly but surely they increasingly desire to make progress in actually doing those things that are pleasing to God.
There is a sense in which the more Christians grow and become closer to the holy God, the more aware they become that they are still unholy sinners. A Puritan once said, "What I once was, I now am not, and what I now am, I will not be." That is, true Christians no longer are dominated by their old, sinful nature, since they are a new creation. Yet, whatever progress believers have made up to the present, they must continue to advance in godliness in the future, so that, as they grow in faith, what they were as Christians in the past they will not be in the future.
So the question presses itself: since Christians do not reach perfection and they sin to varying degrees and in varying ways, and even the most righteous saints become increasingly aware of how sinful they are, how can they be assured that they have a true saving relationship with God? There is no simple answer to this, but there is what may be understood as a cumulative answer that comes from different angles of consideration. We may view the believer's assurance from three angles, with each angle contributing to an aspect of assurance.
Each point of the triangle represents a truth about how a Christian receives assurance.
Trust in God's Promise of Salvation through Christ
First, God promises throughout the NT that those who place their faith in Christ and his redemptive work will receive an inner assurance that they have truly benefited from Christ's work (the top of the triangle). This truth can be found at various places in the NT, 1 John 5:9-15 being a classic example:
If we receive the testimony of men, the testimony of God is greater; for the testimony of God is this, that He has testified concerning His Son. The one who believes in the Son of God has the testimony in himself; the one who does not believe God has made Him a liar, because he has not believed in the testimony that God has given concerning His Son. And the testimony is this, that God has given us eternal life, and this life is in His Son. He who has the Son has the life; he who does not have the Son of God does not have the life. These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life. This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us. And if we know that He hears us in whatever we ask, we know that we have the requests which we have asked from Him.
God "has testified" that "eternal life" comes through belief in "His Son," and those "who believe" in the Son "have the testimony in" themselves (vv.9-12). This "testimony" is none other than the internal witness of the Spirit (see, e.g., 1 John 2:20, 27). We can be assured that God's testimony is true that we have life in the Son, since otherwise God would be a liar (which cannot be [v.10]). The gospel message about the Son is elaborated throughout 1 John and is "written" so that those who "believe in the name of the Son of God...may know that [they] have eternal life" (v.13). Such genuine believers have "confidence" that God hears the prayers of those who pray "according to His will" and will grant "the requests which we have asked from Him" (vv.14-15). In the context, one such implied request is that if they have asked for life in the Son, then on the basis of God's promise to give such life, they can be assured that he has given them this life. Thus, further assurance of genuine faith comes from this confidence that Christians have about the way God responds to prayer.
In sum, in this passage from 1 John assurance of true faith comes from (1) the internal witness of the Spirit; (2) the reliability of God's word that he will give life in the Son to those who believe; (3) the confidence that God hears and answers the faithful prayers of those who ask for salvation in the Son. In fact, the purpose of the entire epistle of 1 John is to give this assurance (v.13).
The role of "good works" is a second angle from which to view the nature of assurance (the bottom left part of the triangle). As we have seen, one who has truly been resurrected (Eph. 2:4-6) and thus becomes a part of the new creation will inevitably and increasingly be characterized by good works (Eph. 2_10) instead of behaving like "dead people" in bondage to "trespasses and sins" (Eph. 2:1-3). Likewise, 2 Pet. 1:3-4 explains that Christians possess God's image (the "divine nature"), and on this basis they are to grow in the fruits of godliness (vv.5-8). Then, on the grounds that believers are expected to have such spiritual traits, the following conclusion is reached in verses 10-11:
Therefore, brethren, be all the more diligent to make sure about His calling and choosing of you; for as long as you practice these things, you will never stumble; for in this way the entrance into the eternal kingdom of our Lord and Savior Jesus Christ will be abundantly supplied to you.
How can believers "make sure about [God's] calling and choosing" (v.10a)? Verse 10b explains the basis for such assurance: "as long as [believers] practice these things" (the godly fruits of vv.5-8), they can be assured that they "will never stumble," which adds to the basis of the assurance in verse 10a. Verse 11 reiterates verse 10: "in this [same] way" of practicing these godly fruits, they can be sure that "entrance into the eternal kingdom...will be abundantly supplied" to them. Thus, assurance of one's "calling and choosing" and final "entrance into the eternal kingdom" increases with growth in doing godly things.
Accordingly, believers' assurance of truly being part of the new creation comes as they look back at their former life and see the changes that have come about since they became Christian. Those who may have grown up from an early age as a Christian may not have such radical differences between their past and present. Nevertheless, they should not be characterized by the kinds of sins that Paul lists in 1 Cor. 6:9-10. Such people also gain a degree of assurance from this recognition. All Christians, to one degree or another, ought to be able to look back and see that they have progressed in godliness during the course of their Christian lives (recalling also that as such growth occurs, ironically so does increasing awareness of remaining sin). This observation ought to bolster Christians' confidence that they are genuine.
Given time, if confessing believers have not changed the ungodly lifestyles of their former unbelieving lives, then such people should not be given assurance that they have truly believed. Perhaps they are true Christians, but they should not have affirmation that they are. Accordingly, the confidence that such persons claim to have from the top part of the triangle is contradicted by the bottom left of the triangle and poses such dissonance that the profession of belief should be questioned. Possibly, such a lack of assurance might shock them either into the reality of their faith, so that they change, or shock them into truly believing for the first time.
Conviction by the Spirit
The presence of the conviction of sin within professing Christians is a third angle from which to understand assurance. As we saw earlier (under the heading "Conclusion: The Purpose of the Commands in the New Testament" above), people who are part of the new creation should be convicted of their sin because of the eschatological Spirit within them. When Christians think or do unholy things, there should be immediate conflict and dissonance with the indwelling Holy Spirit, who is in the process of causing the believer to reach the goal of complete end-time righteousness. Those who are accordingly convicted about their sin will express repentance and change their sinful ways. Those who have no conviction about indwelling sin should have no conviction that they are genuine saints.
Therefore, faithful, growing Christians should receive multiple assurances from these three angles, which have a cumulative force, enhancing the overall sense of confidence about the reality of their Christian existence. What if a Christian is inconsistent in progressing in good works, and an area of life is not under submission to the Lord of the new creation? Such a person should be under great conviction about this sin, and if so, it is a good sign that the Spirit is really in the person, bringing about conviction. Such a person should not doubt knowing God, unless as time goes on the conviction over sin does not issue into repentance, a turning away from the sin being committed.
However, no confidence should exist in those who profess to believe in Jesus but who reflect no discernible change for the good in their lifestyles and who have no conviction about changing their sinful ways.
Generally, the closer people get to God as faith grows, the more such people will desire to please God by what they do, and the more they will be convicted by the remaining sin in them. As a result, they will have even greater assurance as they progress in their Christian lives.