Because we don't know the day or the hour of our Lord's return, we must constantly be ready. The believer who starts to neglect the "blessed hope" will gradually develop a cold heart, a worldly attitude, and an unfaithful life.
2 Peter 3:13,14 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.
Wherefore, beloved, seeing that ye look for such things, be diligent that ye may be found of him in peace, without spot and blameless.
If we are diligent to watch for His return and to live holy and godly lives, then we will not be afraid or ashamed. We will meet Him without spot and blameless.
We must keep "His promise" before our hearts. The promise of His coming is the light that shines in this dark world.
2 Peter 1:19 . . . as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts;
The "day star" will be aglow in our hearts if we love His appearing.