A friend of mine asked me about I John 4:18 which reads:
18 There is no fear in love. But perfect love drives out fear, because fear has to do with punishment. The one who fears is not made perfect in love. (New International Version)
Lets start by looking at the main words in this text: Fear, Love, Perfect, Punishment
The bible has two meanings for the word fear:
1. Respect/ Reverence
2. To be afraid
This passage is talking about #2.
The word for Love John is using is Agape'. I think you have a good grasp on this kind of love so I will not explain it.
Next is Perfect. This word has only one meaning and it is not what we typically think of or mean when we say 'perfect'. Our version of perfect means to be flawless, morally pure, sinless, without blemish, etc. When John uses this word it means: to be whole or complete, not lacking anything.
So when John combines these two, Agape' & Perfect, he is talking about a love that completes us, makes us whole, provides our every need and ultimately casts out any fear we may have about the future (which, as you know, from our perspective is quite uncertain and unpredictable). Picture us as a glass completely empty and the water that fills it all the way to the brim is God's Agape'. It fills us all the way to the top. Nothing else could be nor need be added.
Therefore, (with God's perfect agape' in us) we do not need to be afraid. Particularly of the future, i.e. Punishment; which seems to be John's immediate context for the cause of fear. The reason is that, while God's agape' is perfect, so is His punishment.
This punishment has to do with the coming Judgement John mentions a few sentences earlier. Those who do not have the love of God in them fear this day whereas those of us who do have God's agape in us long for it!
While John is addressing a fear that is specific (the eternal destiny of our soul) I believe this has a broader application. When we fear (eternal judgment or otherwise) it is because we do not trust God's agape' to be perfect and all we truly need. This lack of trust produces in us all manner of fear, doubt and worry: What will tomorrow bring? How will I provide for my family? Will my kids turn out ok? Am I a good parent? Do I have what it takes to accomplish the task God is calling me to? Will I be accepted by others? How will we survive in these troubled times? Will things really be OK? And so it goes.
Agape' expels every fear. I love the way John puts it: Agape DRIVES OUT fear. It is the picture of a strong man plowing every fear out of our path with God's agape. Like Jesus did when he cleansed the temple with a whip!
If we fear something it is because God's agape' has not been made perfect (fully made its way) in us. This compels us to know God more deeply and intimately in order that His Agape' may perfect in us what is lacking and producing our fear. And with Agape' made complete in us nothing can stop us from accomplishing God's will nor delay God from accomplishing His will through us! However, I am afraid (no pun intended) for the most part this is a life long process of learning how to trust God and not an instantaneous act on God's part.
I hope this helps. Let me know if you have any more questions. I am happy to be here for you my friend.