2 Peter 1:9-10

9For whoever lacks these qualities is blind—shortsighted [closing his spiritual eyes to the truth], having become oblivious to the fact that he was cleansed from his old sins.

10Therefore, believers, be all the more diligent to make certain about His calling and choosing you [be sure that your behavior reflects and confirms your relationship with God]; for by doing these things [actively developing these virtues], you will never stumble [in your spiritual growth and will live a life that leads others away from sin];