D. A. Carson once observed a common trend in dealing with truth (particularly Christian truths, but not exclusively): one generation believes it, a second generation merely assumes it, and a third generation ends up denying it.
When discussing beliefs with others, I sometimes get a vague sense that we are merely assuming truth rather than believing it. These assumptions often come pre-packaged in name-dropping and associating with certain movements, spokespersons, groups, or creeds.
I’m guilty of this. I tell others I’m a student at Reformed Theological Seminary and how I memorize portions of the Westminster Shorter Catechism. That stuff counts, right? Or I name authors I read and agree with. And when I’m with certain people who know about all this stuff, we become a bunch of Christian bobbleheads who sit around assuming truth without ever really discussing it. We can even do this with the Bible. We talk about how much we believe the Bible and that it is the Word of God in written form, but we spend very little time discussing what we find in it or how we interpret portions of it or how what implications it has for how we are to believe and live.
Several years ago as a new Christian, I went with a friend to share the gospel with some random people at his church. I had very little idea about what I was getting myself into, but I was paired up with a girl who seemed like she was a pro at that sort of thing. I accompanied her to the bookstore where she approached one lady and immediately asked her, “Do you want to know how to get to heaven?” The lady replied, “I know how — just believe in Jesus.” Then the girl said something to the effect of, “Oh, okay well have a good evening!”
There was a lot of assuming going on in that one instance. I assumed this girl knew what she was doing in sharing the gospel. The girl assumed that to “get to heaven” was an issue the lady identified with. The lady assumed that belief in Jesus was as simple as belief in Santa or the Tooth Fairy. Or maybe she thought that making the claim of belief in Jesus would save her from the judgments of two young religious fanatics.
In the end, what it really comes down to is what I really believe after I’ve wrestled with the truth. What do I really believe about the sovereignty of God? What do I really believe about God or about the gospel? Have I thought out the implications of those things? Do I live as if they are true? Otherwise, I merely assume. And assumption is never the same thing as belief.
Preaching the Gospel to Myself 