A mutual friend, who has never experienced a pregnancy was curious: "Why is that wonderful?"
"Because," I started to answer, and stopped. How do you explain it to somebody who doesn't know? Especially when I, myself, have only experienced it vicariously, through my wife? I understand it. I've felt the baby hiccuping in my wife's womb, and have been pleased and awed and amused. A hiccup, as annoying as it is to an adult (and, let's be honest, probably an unborn baby, too!), is also a wonderful reminder of the little life growing within. Intellectually, I get it. But how do you explain it to somebody who has never had the experience. Why is it wonderful? "Because it is."
It can be just as difficult trying to find words to explain to people why your life is better with Christ. 1 Peter 3:15 tells us to "always be prepared to give an answer" when people ask us about the hope we have. But how? How do you explain it to somebody who simply doesn't know? It's like trying to describe how something looks to somebody who was born blind.
In fact, Paul comments on exactly that problem in 1 Corinthians 2:14:
The person without the Spirit does not accept the things that come from the Spirit of God but considers them foolishness, and cannot understand them because they are discerned only through the Spirit.
The truth is, without asking for the guidance that can only come from God's Holy Spirit, we ourselves can only touch on the outer edges of explaining our hope in Christ. Just as my wife, who experienced her own pregnancies, and my sister, currently going through it, were far more able than I to explain the simple joy of a hiccuping baby, it is only through the Spirit of God that we can begin to describe for others who God really is.
Even then, it can be discouraging as your friend tries to understand what you're telling them, because, unless he or she knows through the experience of the Spirit, he or she simply can't really know. Like my friend who won't fully understand pregnancy until she experiences it for herself, we can't understand God without being given that understanding directly from the source.
So, be encouraged. It isn't our job to guarantee understanding when we tell others what Christ has done for us. We simply need to let the Spirit of God speak through us and, when they're ready, He will give to others the understanding He has given us.