Assurance and Transformation

2 Peter 1:10-15 

10 Therefore, brethren, be even more diligent to make your call and election sure, for if you do these things you will never stumble; 11 for so an entrance will be supplied to you abundantly into the everlasting kingdom of our Lord and Savior Jesus Christ.
12 For this reason I will not be negligent to remind you always of these things, though you know and are established in the present truth. 13 Yes, I think it is right, as long as I am in this tent, to stir you up by reminding you, 14 knowing that shortly I must put off my tent, just as our Lord Jesus Christ showed me. 15 Moreover I will be careful to ensure that you always have a reminder of these things after my decease.

If we do not see enough obvious evidence of the changes in character of thought and deed mentioned in the previous verses (2 Peter 1:5-9), our shortsightedness should cause serious reflection.  Here we are told to ensure our drawing and calling by God and resulting salvation in a rebirth of spiritual life.  If we do none of these things nor desire to pursue them toward holiness, we may not be entering the everlasting kingdom of our Lord Jesus Christ.  We are to settle where we stand in Him to progress further, not doubting if we know the inner change but only struggle outwardly, but testing our condition if we lack these regenerative changes overall.  Therefore as we grow in sanctification in these areas, we are reminded by scripture and those over us in the Lord (1 Thessalonians 5:12, Hebrews 13:7, 17) of these things that we might be further conformed to the image of Christ in us (Romans 12:2, 2 Corinthians 3:18).  This is necessary even for those who are established in this truth, as we all need constant reminding while it is still day and we can see the way to walk.  Peter gives the example here to not let up in reminding God’s people of these things, knowing the time is short for him - he was making the most of his remaining life to help others.  He even made certain there would be others to continue overseeing and ministering to them after he died.  Our assurance of salvation and resulting need for constant sanctifying growth is essential to our own ministry to others as well in the way we are called in Christ by the gifts His Spirit personally gives each of us (1 Corinthians 12:5-7, 11).