Now, here's the thing. I get it. If something is meaningful to you, it is easy to take it's truthfulness for granted. "Of course Christianity is true, Jesus has changed my life." "Of course Christianity is true, I feel the presence of God when I worship." "Of course Christianity is true, I was raised in a family where we saw God answer prayers." For me to call any of that into question is akin to blasphemy for many people. But think about how easy it would be to replace Christianity in that sentence with virtually ANYTHING else. "Of course Islam is true, the teachings of Muhammad have changed my life." "Of course Mormonism is true, I prayed for God to confirm it to me, and I felt the presence of the Holy Spirit." And it doesn't just work with other religions, it works with basically anything that someone might find meaningful. "Of course Oprah is right, she changed my life." "Of course Oprah is right, I grew up watching her, and she always steered me right." "Of course Oprah is right, I feel great when I am watching her show or reading her books." There is no denying that Oprah is very meaningful for a lot of people.
The other problem is that if the reason you are a Christian is because it is meaningful to you, what do you say to someone for whom it is completely meaningless? Well, look around at what most Christians do. They are engaged in trying to convince other people that Christianity really is meaningful. And that leads to a whole lot of frustration. It is like trying to convince an Auburn fan to root for Alabama, or a Yankees fan to cheer for the Red Sox. You almost certainly aren't going to convince them to feel the way you do about it. Sure you can often pass the meaningfulness along to your children, though some just won't be interested, no matter how hard you try. But for the person who has no stake in it at all, or maybe has an aversion to it, and for whom it is impossible to pass meaning along via tradition (like within your own family) the only hope is to simulate the experience for them in some way, hope that they will get a taste, and then encourage them to pursue it further. In my observation, that is basically the way Christian evangelism works in the modern western world. "Come to a worship service and see how it feels." "Just give Jesus a try, follow these principles, and your life will change for the better." But let me ask you again, how well does that usually work out? Put another way, how many times have you watched people come to church for a little while, get really fired up about Jesus, and start making some life changes, only to duck out a few weeks later? And then Christians are incredulous--they just can't believe it. "Sheesh, they just didn't 'get it!'" That's the problem. We often treat Christianity like it is something to "get," instead of something that is true.
Again, don't misunderstand me. I believe Christianity is filled with meaningful experiences, traditions, life changing power etc. But what comes first, meaningfulness or truth? Is Christianity true because it's meaningful or meaningful because it's true. Well, the first can only be true in a subjective sense. And I am afraid that for many, I would even go out on a limb and say that for the vast majority (at least in the western world), meaningfullness is primary. To answer the question, "why are you a Christian" with something as simple as "because I am convinced it's true," is many times even frowned upon for sounding cold, rationalistic, unspiritual, or downright nonsense. It is definitely considered by most people to be totally unhelpful for evangelism. "People don't want to hear that. They need to hear what it means to you." Or you will hear people say, "Everyone is searching for meaning and Jesus is the answer." That may be true, but the trouble comes when we offer up Christianity merely as a way to fill the meaninglessness--Jesus as just someone to find meaning in. We become an evangelistic infomercial. And offering Christianity merely as something to find meaning in, (even though it may be a really really good thing, with lots of great and inspiring stories and a beautiful promise that you can be forgiven and when you die go to the best place ever)--if meaning is all that's there--then it is ultimately like offering a pacifier to a screaming baby. Eventually they will need something real. And if a person has been told that Christianity is only valuable because it's meaningful, they will walk away as soon as it doesn't mean what it used to to them and go looking for something real--with Christianity will be crossed off the list. If Christianity is only true (for the person) because it's meaningful, then that's all you get out of it--a temporary, illusory sense of meaning. Oprah can change your life. Bacon wrapped steak can give you an amazing experience. But if Christianity is true--if Jesus really rose from the dead--if it's really true--and it is--then it is not only meaningful, it changes everything.