What does 2 Peter 1:10 mean?
Earlier, Peter has warned believers that living without the Christlike qualities listed in verse 5 through 7 makes us ineffective and unproductive in our knowledge of Jesus. Such people have become like spiritually blind unbelievers, forgetting they have been forgiven from their sin. Peter now urges his Christian readers to demonstrate the reality of their calling and election.It's important to understand what Peter is not saying here. In no sense is Peter indicating that eternal salvation is based on behavior. Along with the rest of the New Testament authors, Peter has already been very clear that forgiveness of sin is a gift of grace. We cannot earn it, nor can we lose it through our sins, once we have obtained it. We do not have to meet a certain level of holiness in order to keep our eternal destiny.
What Peter does seem to be saying is far more practical. That is, his point relates to how we actually live and behave. In particular, that saved Christians confirm their salvation, for themselves and other people, by possessing these qualities of Jesus. This does not work in reverse: it is not a hard test for salvation. Nor does it imply that salvation is earned by exhibiting these traits.
Rather, the point seems to be that only those who have been chosen by God and called to faith in Christ can truly possess and "abound" in these qualities. Therefore, those who exhibit them have every good confidence in their relationship with Christ. Those who don't will, at the very least, lack that confidence. If you live as only God's children in Christ are empowered to live, Peter says, you won't have reason to doubt or stumble over your faith. Again, his use of the word "fall" is not about a loss of salvation. In context, this is about a season of wasted time, of unproductiveness and ineffectiveness, of near-blindness and indulging in sin we should have left behind.
Peter is speaking most clearly to those who seem to avoid commitment to Christlike living, while still claiming their place in God's family. This is unproductive at best, and dangerous at worst. Instead, Peter tells the reader to be diligent to demonstrate spiritually mature qualities, as confidence-boosters and evidence of their security in Christ.