Think of an old bridge over a stream. Imagine that there are structural defects in the bridge that are hard to see. Here may be hairline fractures that a very close inspection would reveal, but to the naked eye there is nothing wrong. But now see a ten-ton Mack truck drive onto the bridge. What will happen? The pressure from the weight of the truck will open those hairline fractures so they can be seen. The structural defects will be exposed for all to see because of the strain the truck puts on the bridge. Suddenly, you can see where all the flaws are. The truck didn’t create the weaknesses; it revealed them.
When you get married, your spouse is a big truck driving right through your heart. Marriage brings out the worst in you. It doesn’t create your weaknesses – it reveals them. This is not a bad thing, though. How can you change into your glory-self if you assume that you’re already pretty close to perfect as it is?
An excerpt from The Meaning of Marriage by Tim Keller