John suggests that you not only don't have to be afraid of it, you can have confidence when it comes. Yep, by living God's love.
Perfect love casts out fear because fear has to do with punishment.
If I fear the judgement it is probably because I am hanging on to something for which I should be punished. If I've seen and experienced God's love and all that He offers because of His love, then I don't need to fear, not because I am perfect but because He is and His love is in me and so is His life. My task is just to abide in His love so He abides in me. This abiding, according to John, is demonstrated by how we treat each other. If we can't love each other, whom we can see, how can we love God, whom we cannot see.